British Prime Minister Theresa May will on Thursday publish the government's Brexit white paper but may first accept to report back to the Parliament on a regular basis, sources said.

According to sources, May will quarterly report on the progress on Brexit negotiations, demanded by Conservative, Labour and other opposition parties, the Guardian reported.

It comes as Tory rebels (ancestor of the modern Conservative Party) suggest they will not back any further amendments to the Article 50 bill which will be debated in the House of Commons for two days before a vote on Wednesday night.

They said the bill would be sent to the Lords unchanged and that would add pressure to senior Labour figures in considering voting against it.

Shadow Business Secretary Clive Lewis told his Labour party that he would not back the legislation if it was not amended.

With Labour leader Jeremy Corbyn making clear that his party's MPs should vote for Article 50, the move would suggest that Lewis is likely to return to the backbenches.

Dozens of Labour MPs are expected to vote against Article 50, especially those who hold 'Remain in EU'-supporting constituencies, the Guardian reported.

However, the band of Tory MPs fighting against a hard Brexit are indicating they have been largely satisfied by the Prime Minister's promise of a white paper.

Labour and the Liberal Democrats believe there is very little chance of getting enough cross-party votes for amendments.

They had hoped to win support on issues such as guaranteeing the rights of European Union nationals, and a more meaningful vote at the end of the two-year negotiations or protections in the Commons.

MPs will on Tuesday start debating the bill in the Parliament.

The legislation would give May the power to invoke Article 50 and start two years of negotiations to leave the EU.

Amendments laid down include some trying to stop Brexit going ahead, demands for a referendum on the final deal and for British to remain in the single market and calling for effective consultation.

John Penrose, a Tory MP in the European Reform Group that includes dozens of backbenchers who supported Brexit and some who backed 'remain', urged members to respect the referendum result.

"More people voted for Brexit than for anything in British democratic history, ever," he said.

"Those supporting the idea of a second referendum are not being straight with the electorate. They must know that it's not possible to have a referendum once the deal is agreed at the end of the negotiation process — by then we will have left. They are offering a false choice."

The British government was forced to bring legislation to the Parliament after the Supreme Court ruled that May did not have the power to trigger Article 50 without the permission of MPs and peers.

Ahead of the first day of debate, May said MPs faced a "simple decision: Do they support the will of the British people or not?"

"My message to people is very clear," she told the media in Ireland.

"The people of the United Kingdom voted on June 23 last year in a referendum that was given to them overwhelmingly by Parliament. Six to one Parliament voted. The people spoke in that vote, and the majority voted to leave the EU, the job of the government is to put that into practice."

David Davis, the Brexit Secretary, echoed the Prime Minister's words, saying MPs were considering a "very simple question: Do we trust the people or not?"

One MP engaged in cross-party discussions said there was a reluctance of Tory MPs to step out of line, but there were some who were still thinking of ways to use this bill to nudge May away from the hardest Brexit path.

However, a senior Liberal Democrats source said there was "no chance" of getting any substantial amendments passed with cross-party support and the debate was likely to be a "damp squib".

The biggest bloc of votes against Article 50 on Wednesday is likely to come from the Scottish National Party (SNP), whose 54 MPs will oppose the legislation from the outset.

Stephen Gethins, the SNP Europe spokesman, criticised May for failing to publish the promised white paper before the first debate, leaving parliamentarians and the public heading blindly towards leaving the EU and policies based on "soundbites rather than sound arguments".

There is a greater chance the bill could be amended in the House of Lords, although peers would likely avoid the appearance of trying to frustrate the bill because they are unelected parliamentarians.

The government on Monday announced peers would debate the legislation after the February parliamentary recess, after it clears the House of Commons on either 8 or 9 of the month.

Before completing its passage through the House of Lords probably on March 7, the bill will on February 20 be introduced for scrutiny by the Lords, where the government does not have a majority.

That will see the bill repeatedly move between the Commons and the Lords until an agreement is reached on the final text.

May is aiming to have the bill passed through both houses to meet her self-imposed deadline of triggering Article 50 by the end of March.