A newly-elected member of Tendring District Council has quit just a month after polling day – as the council leader warns more resignations could be in the pipeline.

Len Sibbald polled 751 votes for UKIP in the Rush Green ward in Clacton on May 7 as the party took both seats from the Conservatives.

He was part of a breakaway group of nine councillors from the party who joined a Tendring UKIP faction supporting a Conservative-Independent coalition, but was among five of the group who then switched back to UKIP – which has remained an opposition party.

Now Mr Sibbald has announced his resignation for a mixture of personal and political reasons.

The announcement will trigger a by-election in the ward.

Mark Stephenson, UKIP group leader on the authority, said: “I was very sad to hear Len Sibbald has stood down as councillor.

“I spoke in length to Len and a number of factors have contributed to his resignation.

“Despite our best encouragement Len has made his decision and he will be sorely missed having worked with us for so long in the campaign trenches.”

A source told the East Anglian Daily Times there had been a level of “intimidation” against some councillors including posters being put up outside their houses, home visits and phone calls, and added “it had been getting a bit out of hand”.

Mr Stephenson confirmed UKIP would contest the by-election, while a national party spokesman confirmed four Tendring UKIP members remained suspended from UKIP.

Conservative, Neil Stock, council leader, said: “When you have 22 new elected councillors for a party that has never had a seat on the council before there’s going to be a certain amount of instability. It is probably a shock to be suddenly subjected to that level of interest.

“I think it is highly likely we will see more by-elections before the year is out.

“It is for individual members to give their reasons for the split, but those supporting me I think want to do the best for the people of Tendring and that’s what they feel they are doing.

“When no overall party has control we do need to make compromises, work with people we stood against at the ballot box – but that is the challenge of local government.

“This proves I was absolutely right from the outset to try to form a stable administration.

“The by-election will certainly be an interesting campaign, and if we can get the right candidate I am confident we will be able to put up a strong fight and win.”

No-one from Tendring UKIP was available for comment.