By Terri-ann Williams For Mailonline
Published: 09:45 GMT, 3 November 2019 | Updated: 10:03 GMT, 3 November 2019
Dominic Cummings (pictured above) worked in Russia in the 1990s
The Prime Minister's most senior adviser is facing questions from the opposition government over his past in Russia.
A whistleblower is said to have come forward with concerns regarding Dominic Cummings' involvement with people involved in 'politics, intelligence and security' in Russia in the 1990s.
Shadow foreign secretary Emily Thornberry penned her concerns to her Tory counterpart Dominic Raab.
She questioned whether former Vote Leave director Cummings has been granted access to the Government's most sensitive 'top secret' intelligence files.
On Friday, in a letter copied to the heads of MI5 and MI6 and Cabinet Secretary Sir Mark Sedwill, she said Labour did not 'know the veracity of their claims' but felt compelled to inform them.
She wrote: 'I am writing to you based on the serious concerns that have been raised with shadow ministers by an official-level whistleblower.
Shadow foreign secretary Emily Thornberry (pictured above) raised her concerns to her Tory counterpart Dominic Raab
'I feel duty-bound to put to you the concerns raised with the Labour front bench by a whistleblower whose motives we have no cause to question.'
The individual is