A desperate Keir Starmer has congratulated Donald Trump in their first phone call since the Republican's shock election win as he tries to repair ties. 

The premier sent his 'hearty congratulations' to the president-elect amid tensions over Labour activists campaigning for Trump's rival Kamala Harris, and Foreign Secretary David Lammy previously calling Trump a 'neo-Nazi' sympathiser. 

Sir Keir congratulated Mr Trump on his 'historic victory' after US voters returned him to the White House, Downing Street said.

'The Prime Minister offered his hearty congratulations and said he looked forward to working closely with President-elect Trump across all areas of the special relationship.'

The leaders agreed that the US-UK relationship, from defence and security to growth and prosperity, was 'incredibly strong' and 'would continue to thrive for many years to come', No 10 said. 

Sir Keir and Mr Lammy had lunch with Trump at Trump Tower in New York several weeks ago.

'The leaders fondly recalled their meeting in September and President-elect Trump's close connections and affinity to the United Kingdom, and looked forward to working with one another,' No 10 added.

The PM is facing a huge challenge after tensions flared over Labour supporters helping to campaign for Democrat contender Ms Harris. It sparked the Republican's campaign team to file a legal complaint with accusations of 'foreign interference'.

Tories are demanding Sir Keir apologises for previous comments by Mr Lammy and other senior figures. 

The PM has also repeatedly clashed with billionaire Elon Musk, who looks certain to end up playing a key role in the Trump administration.

One senior minister described Mr Trump's return as a 'nightmare', adding: 'We are going to have to deal with a whole new world order. Whether you look at defence or trade or Ukraine or climate change, everything is going to change in ways that are unpredictable and difficult to navigate.' 

Clem Cowton, a board director at trade body Energy UK, warned ministers to learn a 'stark lesson' from the experience of the Biden administration that tackling climate change could not come at the expense of the cost of living.

He added: 'You don't get the chance to make grand plans about climate or anything else if people feel poorer when they go to the polls in five years.'

Labour's former shadow chancellor John McDonnell urged Sir Keir to move further to the Left, saying: 'The key lesson of the Trump victory for us is that Labour has to deliver the significant improvement in quality of life that people can feel or we face the rise of right wing populism that has swept America. Half measures won't be enough.'

Nigel Farage, who has close links to Mr Trump, said the PM would have to 'roll out the red carpet' and hope to find the President-Elect in a forgiving mood.

He told the Mail: 'They are a long, long way apart on most things. Trump does forgive people - although perhaps not straight away. Starmer is going to have to work very hard at it because that relationship is absolutely crucial for trade, defence and intelligence sharing.'

He added: 'Starmer is going to have to make a choice - he can try and strike a tariff reduction deal with Trump or he can cosy up to the EU. He can't do both.'

One senior Labour figure urged the PM to abandon his plan to appoint a Labour grandee to Washington and stick with US ambassador Karen Pierce, who has forged good relations with the Trump team.

'The last think Keir needs now is to have David Miliband blundering in and trying to lecture Trump about his responsibility to the planet,' the source said.    

Rachel Reeves yesterday pleaded with Trump not to go ahead with trade tariffs amid fears of a hammer blow to UK growth.

The Chancellor said she would make 'strong representations' to the president-elect about the damage a protectionist regime would inflict.

Ahead of his bombshell victory in the US election overnight, Mr Trump has boasted that 'tariff' is his favourite word. He has floated a 10 per cent hike in levies on goods imported from around the world - potentially rising to 60 per cent for China.

The aggressive approach has sparked concerns that the new administration will spark a trade war, with analysts already trimming Britain's growth predictions.

Giving evidence to the Treasury Committee yesterday afternoon, Ms Reeves said: 'We're not just a passive actor in this.

'It's a trade relationship with the United States and we will make strong representations about the importance of free and open trade, not just between ourselves and the United States, but globally, and the US also benefit from those that access to free and open trade with us and other countries around the world, and it's what makes us richer as societies to benefit from that.'

Tory former Treasury minister John Glen highlighted that Goldman Sachs had alredy cut UK growth forecasts from 1.6 per cent to 1.4 per cent.

Challenged if it was realistic to seek to influence Mr Trump, Ms Reeves said: 'We've got another couple of months before the inauguration.

'Obviously, you know, we will begin those conversations. We'll prepare for different eventualities.

'I absolutely do not want to sound in any way sanguine. On the other hand, I am optimistic about our ability to shape the global economic agenda, as we have under successive governments.'

Downing Street refused to be drawn on 'future policy discussions' when asked whether Sir Keir was concerned about the prospect of future trade restrictions.

The PM's spokesman said: 'We look forward to working with President-elect Trump including on a wide range of his policy priorities to improve the UK-US trading relations and to support the significant investment relationship that supports millions of jobs across our two countries.

'I'm not going to get into future policy discussions.'

Asked whether Sir Keir would want Mr Trump to refrain from launching a 'trade war', the spokesman said: 'I'm not going to get into policy discussions that we're yet to have with President-elect Trump, but as I say the UK and US have a strong relationship on economic and trade issues and we look forward to continuing to work (together).'

New Tory leader Kemi Badenoch slammed Sir Keir, Mr Lammy and other senior figures for their comments about the president-elect in her debut at PMQs.

She insisted that Sir Keir must invite Mr Trump to visit the UK and address both Houses of Parliament. 

When Mr Trump was last president Labour MPs including Mr Lammy signed an early day motion arguing he should not be allowed the honour during a state visit.

The attack came after the premier opened the exchanges by congratulating the Republican. 

'Having had dinner with president-elect Trump just a few weeks ago I look forward to working with him in the years to come,' he said.

Sir Keir said in a statement said: 'Congratulations President-elect Trump on your historic election victory. I look forward to working with you in the years ahead.

'As the closest of allies, we stand shoulder to shoulder in defence of our shared values of freedom, democracy and enterprise.

'From growth and security to innovation and tech, I know that the UK-US special relationship will continue to prosper on both sides of the Atlantic for years to come.'

Mr Lammy - who once branded Mr Trump a 'neo-Nazi-sympathising sociopath' - said: 'The UK has no greater friend than the US, with the special relationship being cherished on both sides of the Atlantic for more than 80 years. We look forward to working with you and @JDVance in the years ahead.'

Sir Keir ordered Cabinet ministers to stay silent on the election for fear of further inflaming the situation. But MPs have been unable to resist expressing their dismay on social media this morning.

Meanwhile, jubilant Reform MPs have been demanding that Sir Keir uses Mr Farage's close friendship with Mr Trump. 

Government sources have been playing up a private dinner Sir Keir and Mr Lammy had with Mr Trump in New York in September, insisting they had struck up a good relationship. 

But during the bitter campaign Mr Trump's team filed an official complaint with federal election authorities accusing Labour of making 'illegal foreign national contributions'.

Around 100 activists travelled to swing states to canvass for the Harris ticket - although Labour insisted they went at their own expense. 

There was also anger that senior figures from the party went to the Democratic National Convention in August and met Harris aides. The two parties have long-term ties.  

In interviews at the Commonwealth summit in Samoa last month, Sir Keir tried to gloss over fears the spat could derail the Special Relationship if Mr Trump wins.

He insisted that the situation needed to be 'put in perspective' as volunteers from parties have gone to help out in 'every previous election'. 

As a backbench MP in 2018, Mr Lammy wrote in Time magazine: 'Trump is not only a woman-hating, neo-Nazi-sympathising sociopath.

'He is also a profound threat to the international order that has been the foundation of Western progress for so long.'

And in a 2018 Times article ahead of Trump's first visit to the UK, Lammy committed to be one of 'tens of thousands on the streets, protesting against our government's capitulation to this tyrant in a toupee.'

In a round of interviews yesterday, Health Secretary Wes Streeting was asked for his views on the election.

He joked: 'I've got lots of thoughts but not ones I'm going to share as a government minister.' 

Mr Streeting was challenged about a 2017 social media post where he described Trump as an 'odious, sad, little man', adding: 'Imagine being proud to have that as your President.'

He told Good Morning Britain: 'The Prime Minister and the Foreign Secretary have been working hard to build a relationship with President Trump and his team, so that in the event that he is elected as the next president of the United States, we start with the strong working relationship which is in our national interest and in the interests of the United States as well.

'And it's not often I would pray and aid Nigel Farage, the leader of the Reform Party but, as he said overnight, President Trump, you know, he speaks as he finds.

'He had a very good meeting with Keir Starmer not too long ago, and of course, he'll be aware of things that we've we've all said in the past…'

Mr Streeting said: 'The important thing about this relationship, this transatlantic relationship, is one of the most important alliances that Britain has.

'We have shared values and shared strategic interests, and with war on our continent, in Ukraine, war in the Middle East and wider geopolitical threats, it is in the UK and United States' national interests to work closely together. 

'That won't change, whoever the occupant of the Oval Office is, and we only have hours now to wait until polls close.'

Senior government sources have poured cold water on Mr Farage's suggestion that he could act as a 'conduit' between his old ally Mr Trump and the UK government. 

'That's good of him,' one said witheringly.