Nigel Farage says the UK Independence Party (UKIP) is "at war" with the Conservative Party and criticised David Cameron for failing to backtrack on his claim in 2006 that UKIP members were mostly "closet racists".
He also hit out at the Prime Minister for failing to deliver a referendum on the European Union.
More top news
After a frosty start, southeastern areas will be dry with increasing amounts of sunshine developing. It will remain cold throughout the day.
Higher food and petrol prices are expected to send inflation to its highest level in 28 months when official figures are released later.
The Prime Minister will detail her 12-point plan on negotiating Britain's exit from the European Union during a speech on Tuesday.