UPDATE 1-UK proposes customs centers on both sides of Irish border - RTE report

report@ (Adds details, background)

DUBLIN, Sept 30 (Reuters) - Britain is proposing to set up "customs clearance centers" on both sides of the Irish border after Brexit in order to avoid the need for border checks on the border itself, Irish state broadcaster RTE reported on Monday.

The issue of how to manage the Irish border after Brexit has been one of the main obstacles to an exit agreement between the European Union and Britain.

The British government is expected to present new proposals to the EU to try and break the deadlock this week.

"The UK has proposed a string of 'customs clearance centers' on both sides of the Irish border as a key part of its plan to replace the backstop, RTE News understands," the broadcaster's Europe Editor Tony Connelly said on Twitter.

"The 'centers', effectively customs posts, would be located between 5-10 miles (8-16 km) 'back' from the border," he added.

Connelly reported that the details came from technical papers sent from London to Brussels, of which he had seen extracts.

Earlier, a British government source said new proposals would be handed over to EU negotiators on Wednesday or Thursday.

How to handle the border between the Republic of Ireland, an EU member, and Northern Ireland, which is part of the United Kingdom, has proved to be the thorniest issue in the Brexit negotiations.

The Irish and British governments and the EU all say that they want to avoid border checks and physical infrastructure on the border because those could re-ignite tensions over Northern Ireland's political status.

The challenge is how to avoid physical checks on the border after Brexit, while also maintaining the integrity of the European single market.

A proposed withdrawal agreement negotiated by the EU and former British Prime Minister Theresa May - but rejected by the British parliament - contains a mechanism called a "backstop" that would come into effect if there was a failure to agree a long-term trade deal to keep the border open.

Boris Johnson, May's successor, says the backstop is unacceptable and should be scrapped. So far, the government in Dublin and the EU leadership in Brussels have said their position had not changed. They have asked Britain to come up with alternatives to the backstop, and have complained that no workable solutions had been put forward by London.

Johnson has vowed to lead Britain out of the EU by Oct. 31, with or without an exit agreement. However, it is not clear how he plans to do that, as the British parliament has passed a law requiring him to seek an extension to the deadline if no deal is agreed with the EU by Oct. 19. (Reporting by Graham Fahy in Dublin and Elizabeth Piper in Manchester; writing by Estelle Shirbon; editing by Jonathan Oatis and Marguerita Choy)