Britain now faces a compressed timetable to pass all the laws it needs to get ready for Brexit, a spokesman for Prime Minister Theresa May said on Thursday after lawmakers defeated the government on proposed changes to its EU withdrawal legislation.

"This is a very specific amendment which would compress the time we have to pass secondary legislation under Clause 9 in time for exit day, when the withdrawal agreement comes into force, so we now need to consider if further changes are needed," the spokesman told reporters.

He said the government had no plans to withdraw a separate proposal to write into law its 29 March 2019 European Union exit date.