Theresa May faces tricky PMQs as MPs plot dozens of Brexit amendments

Theresa May is to be challenged by MPs to reveal more about the Government's Brexit plans after her Supreme Court defeat on Article 50.

In what could be a testing Prime Minister's Questions, she will be challenged on the legislation the Government has now been forced to introduce.

She will also face potentially embarrassing questions from MPs on the Trident test cover-up row and her meeting with new US President Donald Trump later this week.

But the Article 50 legislation will dominate PMQs and Parliamentary business for the next two months, because MPs are planning to table dozens of amendments.

The chairman of Vote Leave Watch, Labour MP Chuka Umunna, told Sky News: "Parliament is free to add amendments to the Article 50 Bill and the Great Repeal Bill to make sure it delivers, whether they voted Leave or Remain.

"So I would like to see, for example, a commitment to put £350m a week into the NHS that Boris Johnson, Priti Patel, Liam Fox and Chris Grayling committed to during the referendum campaign."

The Scottish National Party has said it will table 50 amendments to the Article 50 Bill, which Brexit Secretary David Davis has told MPs will be introduced in the Commons later this week.

"The SNP forms the real opposition at Westminster and is already preparing detailed and substantive amendments to the legislation that will be required to trigger Article 50," Joanna Cherry QC, the SNP's legal affairs spokeswoman at Westminster, told Sky News.

The Nationalists will also attempt to force the Prime Minister to seek the approval of the devolved administrations - Scotland, Wales and Northern Ireland - before Article 50 is triggered, even though the Supreme Court rejected this in its ruling.

Another demand from pro-Remain MPs on all sides of the Commons is for a Government white paper setting out a detailed Brexit plan, a move Mr Davis has not entirely ruled out.

Former Attorney General Dominic Grieve told Sky News publishing a white paper would be to the Government's advantage, since it would strengthen its hand in Brexit negotiations with other EU countries if it had been approved by Parliament.

But hardline Brexiteers are warning opponents, in the Commons and the House of Lords, against thwarting the will of the people, as expressed in last year's referendum.

"This was the biggest vote in history, for any issue," former Cabinet minister Owen Paterson told Sky News. "If it is seen to be delayed, stymied or watered down, the whole credibility of the political establishment will be damaged. So the House of Lords would be very unwise to delay."

The Prime Minister still insists she will meet her deadline of triggering Article 50 before the end of March, but the timetable is tight and the Government will need to guillotine debate to get the legislation through in time.