FILE PHOTO: Conservative MP Steve Baker attends a meeting of the pro-Brexit European Research Group in London, Britain, November 20, 2018. REUTERS/Henry Nicholls

LONDON (Reuters) - British Prime Minister Theresa May’s government will collapse if she relies on the opposition Labour Party to pass her Brexit deal, an influential pro-Brexit lawmaker said on Friday.

Steve Baker said the Northern Irish party whose 10 members of parliament props up Britain’s government would withdraw support for the government because they are opposed to the inclusion of the so-called Irish border backstop.

Britain’s opposition Labour Party has offered to support the government’s Brexit deal if she makes five legally binding commitments – including joining a customs union.

“Were this deal to pass through parliament with this backstop on Labour votes the government would subsequently collapse because the DUP will not be able to maintain confidence and supply,” Baker told BBC radio.