Theresa May faces a fresh Brexit headache as ministers attempt to avert a Tory revolt over demands for her to set out her plans for negotiations with the European Union.
The Prime Minister has frustrated some on her own benches with her reluctance to spell out her goals and up to 40 potential rebels are thought to be prepared to back a Labour motion on the issue on Wednesday.
May continued to keep her cards close to her chest on a visit to Bahrain, refusing to rule out the UK paying for access to the single market after Brexit and repeating her promise to achieve an "ambitious" deal.
Labour's motion acknowledges that some elements of the negotiating position should remain secret but urges the Prime Minister to "commit to publishing the Government's plan for leaving the EU" before the formal Article 50 Brexit process begins.
Tory former minister Anna Soubry, who backed the Remain cause in the referendum and is now a prominent supporter of the Open Britain group calling for close links to the EU, said she would support the Labour motion unless the Government produces a compromise amendment.
She said: "The Labour motion on Wednesday calling for parliamentary scrutiny of the Government's Brexit plan is eminently sensible and supportable.
"The best solution would be for the Government to unite all sides of the House by now agreeing to put before Parliament their plan for the upcoming negotiations.
"It would be a vital and welcome step in healing the Brexit divisions that exist, not just in politics, but across the country."
Shadow Brexit secretary Sir Keir Starmer said: "Labour accept and respect the referendum and we will not frustrate the process of leaving the EU.
"But Parliament and the public need to know the basic terms the Government is seeking to achieve from Brexit. This issue is too important to be left mired in uncertainty any longer.
"That is why Labour have called this debate on Wednesday. Our motion is simple but would deliver real accountability and grip in the Brexit process. I hope MPs on all sides of the House will join Labour in supporting it."
As she arrived in Bahrain for a two-day visit, May insisted she is "ambitious" for the deal Britain will strike to leave the EU.
Pressed on whether the UK will pay to remain in the single market, May said: "I'm ambitious for what we can achieve in our deal.
"We will be looking to negotiate the best possible terms that we can with the European Union.
"Crucially, this is not about how we retain bits of what we've already got, but what our new relationship with the EU is.
"And I think that's a relationship which is not just a single UK as supplicant into the EU, actually it's about the EU as well, it's about the UK."
Her comments came after Brexit Secretary David Davis said last week that the Government would consider paying to maintain access to the single market for British exporters.