(Bloomberg) -- U.K. Chancellor of the Exchequer Philip Hammond said he would back a legal challenge against the government if the new prime minister tried to suspend Parliament to force through a no-deal Brexit.

Boris Johnson, the favorite to succeed Prime Minister Theresa May this month, has refused to rule out proroguing -- or suspending -- Parliament to fulfill his pledge to leave the European Union on Oct. 31. Though Johnson has said he’s “not remotely attracted to the idea,” he’s keeping his options open.

Such a move would provoke a constitutional crisis because Parliament is “dead-set against” a no-deal Brexit, Hammond said on Bloomberg TV on Friday. “If anybody were to attempt to shut down Parliament in order to carry out a course of action which Parliament is known to oppose, that would be very serious indeed,” he said.

Hammond said he “strongly supports” the position of former Conservative Prime Minister John Major, who said this week he would be prepared to take the government to court if the new premier tried to suspend the legislature. Members of Parliament also voted this week in favor of a plan to prevent prorogation -- the latest attempt to block a no-deal Brexit.

“If we aren’t able to prevent that course of action through Parliament, then certainly there will be resort to the courts,” Hammond said.

On Thursday, Chief Secretary to the Treasury Liz Truss -- a loyal supporter of Johnson -- said prorogation should remain an option, and told Major to stop being “a back-seat driver.”

In the Bloomberg TV interview, Hammond refused to say if he would support a vote of no confidence in the government if it was the last resort to stop a no-deal Brexit, calling it a hypothetical question. He said that while the chance of the U.K. leaving the European Union without an agreement “is not negligible,” he still sees a negotiated exit as the “most likely outcome.”

To contact the reporters on this story: Jessica Shankleman in London at jshankleman@bloomberg.net;Francine Lacqua in London at flacqua@bloomberg.net

To contact the editors responsible for this story: Tim Ross at tross54@bloomberg.net, Stuart Biggs, Emma Ross-Thomas

©2019 Bloomberg L.P.