A former Labour MP has confirmed he will run as an independent in the general election after the party withdrew its support for him after he backed protesters in an LGBT teaching row.

Roger Godsiff, 73, who had been the Labour MP for Birmingham Hall Green, was told this week by the national executive committee (NEC) that he would not be endorsed as a candidate in the December poll and someone else would run in his place.

On Thursday, Godsiff announced he would run for election in his former constituency as an Independent Labour candidate.

He said that “a small intolerant vindictive group within the LGBT community” had carried out a “vicious and vindictive campaign of character assassination against me using social media and misinformation to stir up a witch-hunt”.

The constituency is home to Anderton Park primary school, which was at the centre of a series of school gate protests earlier this year. It led to a court injunction banning demonstrations inside an exclusion zone around the site.

Godsiff was criticised after telling protesters they had a “just cause”. The shadow education secretary, Angela Rayner, reported the “discriminatory and irresponsible” comments to the chief whip, Nick Brown.

He was then reprimanded by the chief whip and instructed not to repeat his comments.

In a statement, Godsiff said: “I have always put the interests of my constituents above everything else and I don’t succumb to threats. I have supported the rights of parents to have a say, not a veto, over how the most sensitive aspects of the Equality Act are taught to young children.”