Nine members, including two former cabinet ministers, of U.K. Prime Minister Theresa May's Conservative Party said they would support a series of cross-party amendments to the EU withdrawal bill, The Guardian reported.

One of the amendments would require a parliamentary vote on staying in the customs union that is expected to pass, according to the report. May has said choosing to remain in the customs union would be a "betrayal" of the Brexit referendum result.

Another amendment would require that parliament be given a voice on what to do if the government's final Brexit deal is voted down. Ministers have told members of parliament that Britain would have to leave the bloc without a deal in such a scenario but some conservative party members have said MPs should be free to consider other options.

The U.K.'s opposition Labour Party said earlier this week that it will propose legislation to prevent Britain's departure from the EU without an agreement with the bloc and demanded that Parliament be given the final say on the government's Brexit deal.

A vote on the proposals is expected to be held after the Easter recess. The group of Conservatives include former party chairman Chris Patten, former agriculture minister Douglas Hogg, former pensions minister Ros Altmann and former newspaper editor Patience Wheatcroft.

Britain and the EU agreed on a draft 21-month Brexit transition agreement, which will allow the U.K. to negotiate trade agreements with other countries and sets out how the country's monetary obligations to the bloc will be calculated.