FILE PHOTO: David Lidington arrives at 10 Downing Street, London, Britain January 8, 2018. REUTERS/Simon Dawson

LONDON (Reuters) - Britain’s parliament would reject Prime Minister Theresa May’s proposed Brexit deal if the vote was held now, her de facto deputy David Lidington said on Tuesday.

Lawmakers will vote on whether to support her deal on Dec. 11, in one of parliament’s most important votes in decades.

“If the vote were today, it would be a difficult one to win, but I think that we have time between now and (Dec. 11) to make the case,” Lidington told Sky News.