DOWNING Street has denied reports that they've fired Tory MP Alberto Costa from his job as aide to Scottish Secretary David Mundell.

The South Leicestershire MP is behind an amendment to be voted on in the Commons tonight, that would force the government to work on a separate agreement with the EU to protect the rights of European Citizens living iin Britain, even if there's a no-deal Brexit.

Costa, who was born in Scotland to Italian parents, managed to secure the support of at least 130 MPs for his amendment, including a significant number of Tories, almost certainly guaranteeing a defeat in the Commons.

There's been some confusion over the government's position on the amendment. 

In Parliament yesterday, Theresa May told MPs it was not legally possible: “A separate agreement for citizens’ rights is something the EU have been clear they do not have the legal authority for.”

But this morning, Home secretary Sajid Javid claimed the government fully supported the amendment.

He told the Home Affairs Select Committee there was “nothing” wrong with Costa’s proposals.

Asked by SNP committee MP Stuart McDonald if the government was now supporting them, he replied: “Yes, what do you mean now? When was the government not supporting it? When did you hear that?”

When McDonald said “Yesterday”, Javid asked: “From who?”

The SNP MP replied: “The prime minister.”

The Home Secretary replied: “Did you? Right... Oh... OK. I’m perfectly happy with the amendment.

“What Mr Costa is doing, which I think is perfectly correct". 

Sources close to Costa claim he was fired this afternoon, but Downing Street insisted he had resigned.

“He has resigned from the government. You will be aware that there is a long-standing convention that members of the government don’t table amendments to bills,” the Prime Minister's spokesman said. 

Mundell paid tribute to his aide, tweeting: "Very sorry to lose @AlbertoCostaMP as my PPS, but fully understand his passion for the issue he is championing today, and which has done since Brexit.

"I am very grateful for his hard work, support and good humour in his time at @UKGovScotland."

Shadow Secretary of State for Scotland Lesley Laird said: “It is a sad indictment on the UK Government that it has refused to unequivocally support a move that simply guarantees EU citizens’ rights in full in the event that we leave the EU without a deal."