The UK will leave the customs union, Theresa May insisted this morning, ahead of a big vote on the issue.
What it means: Politicians in the House of Commons will vote this week about whether or not the UK should stay in its current customs union with Europe. Labour wants to leave the arrangement we've got now, but form a new one.
A customs union means countries agree to set the same taxes (or tariffs) on things they buy from outside. If the UK does stay in this one, or join a new one, it would make it more difficult to form new trading relationships with other countries post-Brexit, the government has said.