British Prime Minister Boris Johnson spent Friday attempting to drum up support for his Brexit deal, telling lawmakers there’s “no better outcome.” A vote in the House of Commons is set for Saturday, in the first weekend gathering since the 1982 Falklands invasion.

Britain is due to leave the European Union Oct. 31, and long has said he is against extending the deadline. Leaving without an agreement could have a severe economic impact and lead to social unrest, according to a report compiled by Johnson’s government.

Johnson needs 320 votes to get his compromise agreement passed. The most support former Prime Minister Theresa May ever mustered was 279 votes.

A BBC analysis indicates Johnson has a solid 302 votes including 272 conservatives, 21 independents and nine members of Labour. But 301 members of Parliament were expected to vote against the pact, which sets up a customs border in the Irish Sea to keep the land border between Northern Ireland and the Irish Republic open. That leaves 36 votes up for grabs, including 15 conservatives and 15 Labour MPs.

Johnson’s deal differs from May’s in that it removes the so-called backstop that could have kept the United Kingdom tied indefinitely to the EU. Johnson’s agreement, however, has not won over members of Northern Ireland’s Democratic Union party, which represents 10 votes. The party has accused Johnson of selling out Northern Ireland, with deputy party leader Sammy Wilson calling it “toxic.”

"There's no better outcome than the one I'm advocating tomorrow," Johnson told the BBC.

MPs adopted legislation last month that would prevent a no-deal Brexit, requiring a letter be sent to the EU seeking an extension of the deadline. German Chancellor Angela Merkel indicated Thursday such a request would be honored.

Labour party officials have warned accepting Johnson’s deal would lead to a period of deregulation that would slash workers rights and environmental protections. Johnson sought to win Labour support by pledging that wouldn’t happen.