A petition calling for a second EU referendum will be debated by MPs later.
The online petition has attracted more than 130,000 signatures since September.
The petition calls for voters to be given a “final say” on the Brexit deal before the 2019 exit date.
The government said Brexit had “the largest democratic mandate in UK political history” and there would be no second referendum.
The petition, which will be considered in a Westminster Hall debate from 16:30 GMT, proposes a referendum with three options for voters:
- to revoke Article 50, thereby keeping Britain in the EU
- to reject the UK-EU deal and leave the EU
- to accept the UK-EU deal and leave the EU
If no deal has been reached by the date of the referendum, the petition proposes the third option could be removed.
The petition was started by Tom Holder, who stood for the Liberal Democrats in Castle Point, Essex, in this year’s general election.
A similar petition last year attracted 4.1 million signatures.
The government said it was its “duty” to “implement the will of the people”, following the 2016 referendum.
“There must be no attempts to remain inside the European Union, no attempts to rejoin it through the back door, and no second referendum,” a response to the petition said.
The government said Parliament would get a “meaningful vote” on the final agreement with the EU before it was concluded, which would give MPs the choice to accept the deal or leave the EU with no agreement.
The Petitions Committee considers all petitions with more than 100,000 signatures for debate.
Petition debates cannot change the law, and MPs do not vote on whether to implement the petition.