Christopher Harborne, the ultra-wealthy political donor who has given £12m to Reform UK, has told the Guardian he is “no longer” interested in a Reform-Conservative pact before the next general election.

A possible collaboration between Reform UK and the Conservative party had been an important aspect of discussions about donations between Harborne and senior figures including Nigel Farage, sources familiar with the conversations said.

The Thailand-based cryptocurrency investor had previously wanted Farage to keep an open mind about a pact between the two parties, the same sources added.

This position has changed, however. Harborne said in an emailed statement: “In the past this was possibly the case, but it is no longer the…