Theresa May is facing a mounting battle to implement Article 50 as a number of MPs have indicated they will vote against the motion.
Last month, the High Court ruled that Theresa May does not have the right to trigger Article 50 without consulting parliament. While the ruling is set to be appealed by the Government in a formal Supreme Court hearing next month, the Prime Minister is - for the moment - unable to trigger Article 50 without Parliament's consent.
Now, a number of MPs have indicated they would oppose the measure to begin negotiations unless there are major concessions.
In particular, Liberal Democrat leader Tim Farron has said that while he respected the decision made by voters, nobody should have a deal "imposed" upon them.
The Lib Dem leader told the BBC: "We believe that what started with democracy last June - which we totally respect - must not now end up with a stitch-up, with a deal being imposed on the British people that absolutely nobody voted for.
"We have said we will vote against Article 50 if our red line is not met, and it is a single, simple red line which is that we want to respect the will of the people.
"That means that they must have their say in a referendum on the terms of the deal. It is the only logical and it is the only democratic option on the table."
While the Lib Dems only have eight MPs, they have more than 100 peers in the House of Lords. This could be problematic for the Government if the judges rule that a full act of Parliament is required before Article 50 is implemented - in order to be come law, a bill must be approved by both Houses.
MPs from other parties have also suggested that they would be prepared to oppose Article 50.
Catherine West, the Shadow Foreign Office minister, tweeted earlier this month that she would "stand" with her constituents, who voted to Remain.
She said: "I stand with the people of Hornsey and Wood Green, and I will vote against Brexit in Parliament,"
Another Labour MP, Helen Hayes, said she would be prepared to defy the party.
She told the Today programme: "I had somebody in my surgery last week who was in tears because of Brexit and I see genuine distress amongst my constituents about what this path means.
"I would not be representing them if I voted to trigger Article 50 on the basis of no information from the Government about the path that they would then take us on."