Theresa May calls for unity on Brexit as pressure mounts to reveal plans

Theresa May is facing threats from both the Labour party and the Lib Dems in a bid to disrupt her plans for triggering Article 50, if she is unable to persuade the country’s most senior judges to overturn last month’s decisive High Court ruling.

She is also faced with a challenge in the Commons later this week – including from within her own party – as MPs attempt to force the Government to show its hand ahead of formal negotiations.

But Mrs May has called for unity across all political groups, as she warns critics they must work with her if the UK is to secure a favourable exit deal.

The Prime Minister’s opponents set out their red lines for Brexit in anticipation of this week’s pivotal Supreme Court hearing. The case, which determines whether or not MPs will be given a vote on triggering Article 50 – the mechanism that begins the formal process of leaving the EU. The High Court ruling was won by Gina Miller, 51, an investment fund manager and philanthropist who was selected to bring the lead case.

Former Lib Dem leader Nick Clegg has stated his party would be willing to back legislation if the Government offers the public a second referendum on the final deal. While Labour leader Jeremy Corbyn has called for continued access to European markets and the preservation of workers rights.

Mr Corbyn is also among a number of Labour MPs leading a debate tomorrow challenging the Government to commit to publishing its plan for leaving the EU before Article 50 is invoked.

The vote will provide Mrs May with an indication of the scale of Parliamentary opposition she faces - including from members of her own party. There are reports that as many as 40 Conservative MPs could back the motion, including the outspoken former minister and remain campaigner Anna Soubry.

Ms Soubry said yesterday that she had read the motion and could not “see anything in it I don’t approve of and could not support”.

However, the Prime Minister’s official spokeswoman appeared to admonish those threatening to rebel or amend legislation, accusing them of trying to “tie the Government’s hands” in negotiations.

She said ministers want to see “everyone to be coming together” to focus on getting the best results for Britain from the process.

She added: “While others are seeming to make clear that they want to frustrate the will of the British people by slowing down the process of leaving the Government is getting on with respecting what the British people decided and making a success of Brexit. It’s very important that we are able to get the best deal possible, and that means not having our hands tied in negotiation.the negotiation and get the best deal possible.”