Theresa May, UK prime minister, arrives for a meeting with Donald Tusk, president of the European Union (EU), in Brussels, Belgium, on Thursday, Feb. 7, 2019. (Photo: VCG)

British Prime Minister Theresa May was set to visit Dublin Friday in her latest bid to rescue her Brexit deal after failing to win any major breakthrough during talks with the European Union (EU).

May returned to Downing Street Thursday after being told during series of discussions that the EU would not budge on its insistence of a so-called backstop insurance policy aimed at avoiding a hard EU-British border on the island of Ireland.

The EU offered more talks with the British government to help May get her Brexit deal through the House of Commons, but the prime minister is seeking legally binding words over the backstop to win a majority vote for her deal.

European Commission President Jean-Claude Juncker ruled out changes to the deal already agreed between Brussels and May's government, but told her he would be open to adding words to a non-binding document on future relations between the two sides.

Ahead of a meeting Friday evening between May and Irish Prime Minister Leo Varadkar, Britain's Attorney General Geoffrey Cox was meeting his counterpart in Dublin, Seamus Woulfe.

Varadkar, meanwhile, headed across the border for discussions on the Brexit impasse with leaders of political parties in Northern Ireland.

Currently the border between the two sides are frictionless, but when Britain leaves the bloc in less than 50 days time, the 500-kilometer meandering line will become the only EU-Britain land border within the British Isles.

London, Dublin and Brussels have all insisted they do not want to see a return of a hard border, fearing it could fuel a return to troubles.

In other developments, the leader of Britain's main opposition Labour Party, Jeremy Corbyn, has written to May with a six-point plan he says could resolve the Brexit impasse.

Labour's proposal to back May's deal has provoked widespread fury among Remain-backing MPs who want to see a second referendum.

John McDonnell, Labour's shadow chancellor, wrote to MPs Friday insisting a new-referendum option remained one of the party's options in the event of a no-deal Brexit emerging as an outcome.