The government is gearing up for what could be its first defeat on the Brexit bill. Theresa May needs the bill approved by the House of Lords before triggering Article 50 and beginning Britain's exit from the EU.

The issue is that the House of Lords may request a unilateral guarantee about EU nationals' right to stay in the UK.

This puts the Prime Minister under pressure to stick to the Brexit timetable as it could mean a delay of up to a week, preventing her from triggering Article 50 before the end of this month and prolonging uncertainty for law firms and other businesses alike.