A major Tory donor has said he will "lend" his vote to another party at tomorrow's European elections.
Lord Kalms, a former Conservative Party Treasurer, said he would be backing one of the smaller parties - potentially UKIP.
The eurosceptic peer's intervention risks disciplinary action, as the Tory leadership takes a dim view of members encouraging support for political rivals.
Businessman Stuart Wheeler was expelled from the party earlier this year after giving £100,000 to UKIP.
In a statement Lord Kalms, ex-boss of retail chain Dixons, said: "European elections tomorrow are a unique opportunity for the British electorate to express their distaste for several current UK policies from all the leading parties.
"It is an opportunity to vote for personal priorities and, with the exception of the BNP, I would strongly recommend, as I will do, voting for smaller parties who represent my major concerns today.
"For myself, I am considering lending my vote to UKIP."