Britain’s parliament has dealt Prime Minister Theresa May’s government a narrow defeat by passing an amendment that puts roadblocks in the path of a “no-deal” Brexit.

Legislators on Tuesday backed an amendment to the Finance Bill that would prohibit the government from spending on preparations to leave the European Union without a deal unless authorised by parliament.

The 303 to 296 defeat highlights May’s weak position just days before she is due to hold a pivotal vote on whether to approve the Brexit deal she has negotiated with the EU.