The government has survived an attempt by pro-EU Conservative MPs to change its post-Brexit trade strategy.
The MPs wanted the UK to join a customs union if it does not agree a free-trade deal with the EU.
But the government, which says being part of a customs union will prevent it from striking international trade deals, won the vote by 307 to 301.
It did, however, lose a separate vote on its Trade Bill on the regulation of medicines after Brexit.
MPs backed an amendment that would keep the UK in the European medicines regulatory network.
The UK is due to leave the EU on 29 March 2019 but the two sides have yet to agree how their final trading relationship will work.
The Commons has been debating two pieces of legislation – on customs and trade – and there have been several attempts to change them by both pro-Brexit and pro-EU MPs.
The latest key vote was on customs, with a debate sparked by Tory MP Stephen Hammond’s amendment to the Trade Bill.
It stated that if a free trade area had not been negotiated by 21 January, ministers must change tack and start discussions on joining a customs union.