Britain and the European Commission have "jointly agreed" to postpone the next round of Brexit negotiations by a week, the UK's Department for Exiting the European Union said Tuesday.
"The UK and the European Commission have today jointly agreed to start the fourth round of negotiations on September 25," a government spokesman said in a statement.
"Both sides settled on the date after discussions between senior officials in recognition that more time for consultation would give negotiators the flexibility to make progress in the September round," he said.
Negotiating teams for Britain and the EU had been due to reconvene in Brussels next week for a fourth round of talks.
An EU source in Brussels told AFP that "the UK political calendar" was the reason behind the postponement.
The last round of negotiations was held in late August and ended with each side blaming the other for the lack of progress.
The outstanding financial settlement of Britain's exit proved to be a major stumbling bloc.
The settlement is estimated at up to 100 billion euros in Brussels but at just 40 billion euros in London, according to reports there.
The EU's chief Brexit negotiator Michel Barnier also voiced concern at London's proposal for the Irish border, insisting that Brussels would not let Britain use Ireland as a "test case for future EU-UK customs relations".
The EU has refused to broach any aspect of the future trade relationship until Brexit talks have achieved sufficient progress on citizen's rights, the Irish border and Britain's financial bill for leaving the EU.