LONDON — The British government is fighting back against criticism that it is divided and unprepared for Brexit, announcing it will publish a set of detailed proposals on customs arrangements, the status of the Ireland-Northern Ireland border and other issues.

The Department for Exiting the European Union said Sunday that it would release the first set of position papers this week, more than a year after Britons voted in a referendum to leave the European Union.

The government says it hopes to persuade the 27 other EU nations to start negotiating a “deep and special” future relationship that would include a free trade deal between Britain and the EU.

The EU says those negotiations can’t start until sufficient progress has been made on three initial issues: how much money the U.K. will have to pay to leave the bloc; whether security checks and customs duties will be instituted on the Irish border; and the status of EU nationals living in Britain.

The exit bill, estimated at tens of billions of euros, is to cover pension liabilities for EU staff and programs Britain committed to funding over the next few years.

The government’s Brexit department said Britain wants to show that progress on the preliminary issues has been made and “we are ready to broaden out the negotiations” by the time of an EU summit in October.

“Businesses and citizens in the U.K. and EU want to see the talks progress and move towards discussing a deal that works for both sides,” the department said in a statement.

EU officials have expressed impatience with the pace of Britain’s preparations.

The bloc’s chief negotiator, Michel Barnier, said last month there was “a clock ticking” on the talks. Irish Prime Minister Leo Varadkar said last week that Brexit advocates “already had 14 months” to issue detailed proposals, but had not.

Barnier is due to meet Britain’s Brexit minister, David Davis, for a new round of negotiations at the end of August.

Britain voted to leave the EU in June 2016, but did not trigger the formal two-year exit process until March.

Prime Minister Theresa May then called a snap election in an attempt to increase her Conservative Party’s majority in Parliament and strengthen her negotiating hand. But voters did not rally to her call, leaving May atop a weakened minority government.

In recent weeks, with May on her summer vacation, members of her Cabinet have openly disagreed about what direction Brexit should take.