Ukip leader Nigel Farage says that it is extraordinary that the electoral law allows groups to be set up to campaign against Parliamentary candidates.

Although he chose not to name it, his target was the Thanet Stand Up To Ukip campaign group, which has been active throughout the campaign in the seat he hopes to win on Thursday.

While parties standing for election are required to be registered with the Electoral Commission, no such requirement applies to campaign groups.

The Thanet Stand Up To UKIP group has been under the spotlight recently amid claims by Green Party candidate Ian Driver that it sought to persuade him not to stand to enhance Labour's prospects.

Today, the group held what was described as a "day of action" in Ramsgate which included picketing the Ukip party HQ in the town centre.

When asked if he felt that last few days of the campaign would see attempts by opponents to smear UKIP, Mr Farage said:

"It couldn't really get much worse locally. Some of what has gone on here is absolutely vile and I am amazed that the electoral law allows an organisation to be set up to campaign against a party. It is pretty clear they are in cahoots with one of the parties but that aspect has been quite extraordinary. Funnily enough, I think now it is having a counter-productive effect."

He also rebuffed the suggestion that if he became an MP, it would be difficult as party leader to focus on constituency matters.

He said that often MPs claimed to be able to resolve constituents' concerns which were the responsibility of the local council.

"Actually, it is Thanet council that will decide on issues like Manston airport; it is the council that will decide on the ferry port; on dog fouling and how the town centres look."

"MPs masquerade very often say they will do things that are really the job of the councillora. We will run our case work and our surgeries together jointly as a team between me and local councillors. We have made that clear at every public meeting."

Meanwhile, Conservative candidate Craig Mackinlay and his predecessor Laura Sandys campaigned together today in Sandwich, Ramsgate and Broadstairs.

Mrs Sandys said: “Craig is a superb candidate and will fight tooth and nail for South Thanet if elected. Only the Conservatives, led by David Cameron, are in the position to win a majority and give the country the strong, stable and competent government it needs.”