British Prime Minister Theresa May could be under pressure to give extreme Eurosceptic Nigel Farage a key role in Brexit negotiations if she strikes an alliance deal with Northern Ireland's Democratic Unionist Party (DUP), according to new reports.

Senior figures in the DUP have told May that she should keep Farage close and allow him to contribute to EU talks in an effort to prevent him from returning to the helm of UKIP, the party he once led, and launching a counter-campaign against her Conservative party, sources told the Sunday Times.

The figures have also suggested that Farage's suspected return to UKIP could be abated with the promise of a peerage. Farage is said to have been in talks with Arron Banks, one of the party's biggest donors, on Friday to discuss the future of UKIP, one of the Conservative's closest competitors.

"They hold a few cards," the source said. "They want Farage as a lord or a role in government or he and Arron will put something together that will cause trouble for May."

Farage stepped down as leader of UKIP following the U.K.'s 2016 EU referendum in which he and his party were instrumental in driving the leave campaign. Speculation over his possible return to the political spotlight remerged on Friday, however, in the wake of the U.K. election, which saw a devastating defeat for UKIP and in particular its leader Paul Nutall, who failed to be elected.