Brexit supporters hold a placard in front of anti-Brexit demonstrators during a protest opposite the Houses of Parliament, London, Britain, December 4, 2018. REUTERS/Henry Nicholls

LONDON (Reuters) - A senior lawmaker in Prime Minister Theresa May’s Conservative Party said he would vote against her Brexit deal and predicted parliament would reject it by at least 80 votes, The Telegraph newspaper reported.

“Brexit should be an opportunity for our country to spread its wings, not have them clipped,” Mark Harper, who formerly served as Conservative chief whip, or parliamentary enforcer, told the newspaper.

“The Cabinet’s proposals are not acceptable because they threaten the integrity of our country, keep us trapped indefinitely in a customs union and leave us in a weak negotiating position for our future relationship,” he said.

Harper said May would lose the Dec. 11 vote “by at least 80” and urged May to renegotiate the withdrawal agreement.