She told the House: "This is a blatant piece of bullying that goes to the very heart of democracy".
The MPs, who include three former Cabinet ministers, are understood to oppose her proposal to enshrine in law the date of Brexit as 29 March 2019.
"If fighting for the best possible future for our country and our government is considered mutiny - then bring it on", tweeted one MP, Heidi Allen.
The pro-remain MP told the Commons on Tuesday night she regarded being labelled a mutineer by the Telegraph as "a badge of honour".
Criticism of the bill was initially focused on its provisions to give powers to ministers to amend the European Union law as it is moved across.
The government said it wants an implementation period of around two years after Brexit to stop an economically damaging "cliff-edge" - but insists Britain will be fully out of the EU.
They argue that the move will limit the Prime Minister's flexibility if negotiations with Brussels drag on until the last minute.
Last week the prime minister vowed that the United Kingdom would leave the EU at 11pm on March 29, 2019, and tabled an amendment to her European Union (Withdrawal) Bill.
Brexit minister Steve Baker also responded to the Telegraph's front page on Twitter, saying he regretted "any media attempts to divide our party".
"We are leaving the European Union in March 2019, so this is not about if, or when, we leave the European Union - those things are settled".
"My Parliamentary colleagues have honest suggestions to improve the Bill which we are working through and I respect them for that", Mr Baker said.
"We're going to leave".
Grieve said that no amount of "arm twisting" would make him vote for the amendment, which will not be voted on until next month towards the end of the bill's committee stage. If I wanted to do that, I would not have supported Article 50.