Most Labour MPs are to the Left of Keir Starmer - suggesting the PM could face pressure to be more radical.
A study asking councillors to rate the views of their local MP has given Sir Keir a score of 48 out of 100.
That puts him almost in the exact political centre, having shifted four points to the right since the exercise was carried out in the last Parliament.
But other Labour MPs are clustered around the mid-30s, often backing more extreme policies.
Academics asked 1,006 local councillors to rate their MPs and compare them to party leaders.
Professor Chris Hanretty, who carried out the analysis, told The Times: 'Before Brexit, I would have said it was normal for prime ministers to be more centrally located than most of their party.
'Cameron was to the left of the Conservative Party, just as Blair was to the right of the Labour Party. I think the same would probably be said of Wilson.'
He added: 'Judgments are personal, but these measures should give similar results if you were to repeat the exercise tomorrow.'
In contrast, Kemi Badenoch was seen as to the right of her Parliamentary party.
Her score of 88 was close to Nigel Farage on 90, while Rishi Sunak was at the centre of gravity on 77.
Only four of the Tories’ 121 MPs were deemed to be further Right than Mr Farage, including Dame Priti Patel, the Shadow Foreign Secretary, Kenilworth and Southam MP Jeremy Wright, and Suella Braverman.
Mrs Braverman, a former home secretary, and Reform’s Rupert Lowe were jointly scored as the most Right-wing MPs in the new Parliament from any party.
Labour's Diane Abbott and Nadia Whittome were seen as the most left-wing MPs with a score of 4.
The most Right-wing Labour MP is Imogen Walker, who is married to Morgan McSweeney, Sir Keir’s chief of staff.
There was not much overlap between Tory and Labour MPs, although Rebecca Harris, deemed the most Left-wing Conservative MP, has seven Labour MPs to the Right of her.
Meanwhile the range of scores for Liberal Democrat MPs was almost identical to Labour’s.
This raises questions about how Lib Dem leader Sir Ed Davey will distinguish himself from Sir Keir and ensure his party becomes more than simply a haven for ‘protest’ voters.
The findings in the research from Royal Holloway University of London and Survation emerged as Elon Musk launched his latest attack on Sir Keir.
Responding to a story about Scottish politicians urging him to invest in a Tesla gigafactory, the billionaire posted on his X social media site: 'Very few companies will be willing to invest in the UK with the current administration.'
Downing Street insisted Sir Keir was running an 'unashamedly' pro-growth government, but refused to criticise Mr Musk directly.
Asked about Mr Musk's view about the government being anti-business, the PM's spokesman said: 'We look forward to working with President-elect Trump and indeed his team to progress the UK-US special relationship, and particularly the UK-US trade and investment relationship, which supports hundreds of thousands, if not millions, of jobs both sides of the Atlantic, and tens of billion pounds of investment and trade.'
He added: 'I'm not going to kind of get into commentary on individual comments, but if you look at what's happened since the election, you've seen the £63 billion of additional investment from the Investment Summit.
'You've seen the Government respond to some of the businesses' key concerns in the UK, which is lack of stability, and the Government's brought back that stability, both politically and economically.'