British lawmakers defeated Prime Minister Theresa May in a symbolic vote over her Brexit strategy on Thursday, undermining her pledge to European Union leaders that she can get the unpopular divorce deal approved if they grant her concessions.

Lawmakers defeated the government 303-258 on the main motion asking them to reaffirm support for her plan to seek changes.

While the vote does not force the government to change tack, the numbers will undermine EU leaders' confidence that May can win parliament's support for a revised agreement.