Paul Nuttall, UKIP's deputy leader, says any election pact with the Conservatives would be "very difficult" while David Cameron heads up the party.
"You really can't believe a word he says on the European Union and he's also a guy who called us closet racists," he said.
More top news
Train operating companies are failing to properly inform passengers about their rights, according to Which?
The average house price in a UK city has surged by nearly a third over the last five years, a shocking report has found.
Former foreign secretary David Miliband says he is 'deeply concerned' and refuses to rule out a future run for the Labour leadership.