The UK Independence party has suspended one of its election candidates who suggested that mothers carrying foetuses with Downs syndrome or spina bifida should be forced to have abortions to avoid the child being "a burden on the state as well as on the family".

Ukip had initially backed Geoffrey Clark, saying that members held "a range of views and opinions" that were not party policy and adding that while it disagreed with his comments, they were contained in a "personal manifesto".

But following a backlash, the party performed a u-turn and said in a later statement the views of the would-be Kent county councillor were "abhorrent" and that he would not be standing for the party again.

"Ukip reject the abhorrent views expressed in the personal manifesto of Mr Geoffrey Clark, a candidate in the local elections," said a spokesman who said that Ukip wanted to apologise to anyone who has suffered distress as a result of this matter. .

"The party was not aware of these views when it allowed him to stand under our name."

Clark – who is seeking seats on Kent county council and Gravesham council in a byelection later this month, as well as to Ukip's national executive – said in a self-styled "personal manifesto" on his own website that there should be a review into various drastic measures to reduce spending on the NHS, such as "giving free euthanasia advice to all folk over 80 years of age".

Among the ideas listed for discussion by Clark, who is also contesting a Gravesham borough council by-election on Thursday, was "compulsory abortion when the foetus is detected as having Downs, spina bifida or similar syndrome which, if it is born, will render the child a burden on the state as well as on the family".

In a "clarification to avoid confusion and misrepresentation" on the website, the 66-year-old chartered accountant stressed that neither he nor Ukip specifically endorsed the ideas, adding: "They are suggestions of matters for the review body to properly consider, in light of the stated desire of all political parties to reduce the national debt."

The manifesto was condemned by Mencap, which campaigns for people with learning disabilities. Mark Goldring, the charity's chief executive, said Mencap was "disgusted and horrified". He continued: "Much has been written about the Paralympics this summer changing attitudes towards disabled people for the better. Yet in the very same year, a council candidate has proposed forced eugenics against disabled people.

"It is abhorrent that Geoffrey Clark sees disabled people solely as a burden, when people with a learning disability lead full lives, and make valuable contributions to their communities and families. We question if he is fit for public office."

Clark's manifesto contains a number of other ideas that will raise eyebrows among Ukip hierarchy as the party attempts to enter the mainstream and shed its image as, in David Cameron's now revoked words, "fruitcakes, loonies and closet racists".

On immigration he calls for the immediate deportation of "riff-raff" elements, demands the revision of passages of the Qura'n and quotes seven verses of a self-penned poem about defending British culture titled, We Must Turn The Tide, And Then Advance.

Clark told the Guardian that he did not support the forced abortion idea but did want to create a debate on how the NHS could be financed in the future. He said: "Those are suggestions for a review body to consider when they look into whether the NHS is affordable in the future. I do tend to provoke thought by throwing out ideas. I do like to be provocative.

"But they're not necessarily my views. I'm throwing out matters for the review body to consider. I'm not qualified to consider them. Therefore they are not my views, as I don't have the qualification to hold those views."

Clark said he apologised for any offence. Asked if he regretted raising the idea he said: "I regret articulating it in the way I have, and I'm going to rewrite it."

Clarke said he knew one person with Downs syndrome and thought he knew one person with spina bifida. Neither were a burden on their families or the state, he said.