LONDON -- Britain might seek to remain in a customs union with the European Union for a time to avoid border chaos after leaving the bloc, the government's Brexit department said Tuesday.

The Department for Exiting the European Union said there could be "a temporary customs union between the U.K. and the EU" to help businesses make the transition to life outside the EU.

And it said a future "customs partnership" could eliminate the need for a border for goods travelling between Britain and the EU.

Brexit Secretary David Davis said the transition period would likely last about two years, and would be replaced by a new deal offering "extremely slick, extremely streamlined customs arrangements."

Some British businesses have accused the government of being vague about whether there will be economic barriers with the EU after Brexit in March 2019. The persistent uncertainty -- 14 months after Britain voted to leave the EU -- is weighing on the economy.

Trade Secretary Liam Fox and Treasury chief Philip Hammond wrote in the Sunday Telegraph that in 2019 Britain will leave both the EU's single market in goods and services and its customs union.

The single market ensures tariff-less trade in goods and services and is linked closely by the EU with other rights, such as the right of EU citizens to cross borders. The customs union allows goods to move within the EU without checks, but also imposes tariffs on imports from outside the EU. That would prevent Britain striking new free trade deals while it remains inside the arrangement.

The British proposal says the U.K. should be free to negotiate new trade relationships during the transition period, something EU officials are likely to find problematic.

EU officials say Britain's stated goal of "frictionless" trade is impossible outside the single market and customs union.

The British government is trying to rebuff claims by EU officials that it is has been underprepared for divorce negotiations before a new round of talks in Brussels at the end of this month.

The customs proposals are the first in a series of papers covering thorny issues in the negotiations. Another, on the status of the border between Northern Ireland and the Republic of Ireland, is due to be published this week.

The European Commission said it took note of Britain's suggestions, "but we will only address them once we have made sufficient progress on the terms of the orderly withdrawal" from the bloc.

The EU says negotiations on its future relations with Britain can't start until sufficient progress has been made on three initial issues: how much money the U.K. will have to pay to settle its outstanding commitments to the bloc; whether security checks and customs duties will be instituted on the Irish border; and the status of 3 million EU nationals living in Britain.