A feud between two of Theresa May’s closest female aides has ended up on the desk of the head of MI6, sources claimed last night.

Security chiefs were drawn into the bad blood between former No 10 advisers Fiona Hill and Katie Perrior over claims that Hill, the PM’s former chief of staff, overruled intelligence warnings about inviting Donald Trump to Britain on a state visit.

The toxic suggestion that British spies warned the Queen off hosting the President risks dragging May into the US probe by Robert Mueller into President Trump.

The anonymous allegation was made last year to an American newswire in a report that also quoted Perrior, Mrs May’s former spin doctor, who clashed heavily with Hill in No 10.

Katie Perrior (right), Theresa May's former spin doctor, is said to be involved in a feud with ex-chief of staff Fiona Hill (left). Both women left Mrs May's service around the 2017 Election

In a slew of articles in the wake of them both leaving Mrs May’s service around the 2017 Election disaster, Ms Perrior took aim at Ms Hill.

Now The Mail on Sunday has learnt the report by Bloomberg sparked uproar at MI6’s Vauxhall Cross HQ.

The report into relations with the White House said Hill was keen to keep Trump close but ‘senior diplomats and the UK security services had other ideas’.

And it quoted Ms Perrior saying that ‘senior diplomats and civil servants’ had ‘raised their concerns’ against inviting Mr Trump on a state visit. But angry security sources say no such warning from ‘security services’ was ever made.

The toxic suggestion that British spies warned the Queen off hosting the President risks dragging Mrs May (pictured) into the US probe by Robert Mueller into President Trump

The MoS can reveal that MI6 bosses have ‘looked into’ the source of the claim of security services involvement and were furious at its implications.

Given that Ms Perrior was quoted extensively, the finger of blame was pointed at her – but she strenuously denies being the source.

An official told this newspaper: ‘Vauxhall Cross were hopping mad and this was handled at a very senior level. The claims are the work of a fantasist.

‘Former government officials publicly saying people had “raised concerns” risks a transatlantic firestorm as the Americans can ask, “What do you know that we don’t?”

Last night Ms Perrior denied she was behind the briefing, saying: ‘If an investigation did take place, and that’s a big if, it was a pretty poor effort considering nobody contacted me, therefore I conclude they ruled me out of being involved.’