In an abusive letter, the BNP candidate for Croydon Central has called Conservative Gavin Barwell a “traitor” to his race and said he would like to see him “hung for treason”.

Cliff Le May, wrote to Mr Barwell at his campaign office after he received David Cameron’s letter urging residents not to vote for Andrew Pelling.

The letter, which was seen by Mr Barwell’s wife and his seven-year-old son reads: “You dirty, sleazy scumbags. If I have my way I will see you all hung for treason.”

Mr Barwell said he received the letter after a long day on the campaign trail and because he was tired, left it out when he went to bed, where it was seen by his family.

He said: “I just think it shows what kind of people these are. I don’t understand why people, when they have different views, can’t just be polite about it.

“If he wants to write to me about being in the EU or immigration that’s fine, but there is no need for personal abuse.”

Mr Le May was unrepentant when asked why he wrote the letter.

He said: “I am referring to the entire Conservative Party – they are dirty, sleazy scumbags. This is a personal view, not a party view.”

Mr Le May did not think his letter was “harsh” and did not care his words had been seen by a child.