One of several votes yesterday was on whether the bill should include a line repealing the 1972 act - crucial to taking us out of the EU.
Michael Tomlinson, MP for Mid Dorset and North Poole, told the Prime Minister it is the "duty" of MPs to "scrutinise, debate, consider amendments" the EU Withdrawal Bill but without standing in the way of the referendum decision.
Another, Anna Soubry, said it was a "blatant piece of bullying" and insisted none of those named wanted to delay or thwart Brexit.
The Daily Telegraph's controversial front page today pictures the 15 Conservative MPs that they say are trying to derail Brexit.
MPs had their first chance to scrutinise the EU withdrawal bill, which would formally end Britain's membership of the European Union and transfer four decades of EU legislation into United Kingdom law.
Heidi Allen, a Tory MP also pictured on the newspaper's front page, tweeted: "If fighting for the best possible future for our country and our government is considered mutiny - then bring it on".
But critics warn the European Union withdrawal bill - also known as the repeal bill - represents a power-grab by ministers, while others see the legislation as a chance to shape the prime minister's Brexit policy.
It passed at second reading, meaning MPs agree with it in principle, but will now be reshaped to make sure it works and try and make it pass in the House of Lords. We want a good Brexit not a hard ideologically driven Brexit.
He said: "I have to say I find this amendment by the government so very unusual, because it seems to me to fetter the government, to add nothing to the strength of the government's negotiating position, and in fact potentially to create a very great problem that could be brought back to visit on us at a later stage".
Labour's shadow Brexit secretary Sir Keir Starmer said setting a date in law was a "desperate gimmick" that was "about party management, not the national interest".
To that effect, it has tabled its own amendment putting the date of Britain's departure onto the face of the bill, which was being debated later on Tuesday, although not taken to a vote.
"And, there is, of course, a lively debate going on in this place, that's right and proper and important".