A legal challenge could scupper the second stage of trials of a scheme requiring people to show ID before they vote.

The case is being brought by Neil Coughlan, a 64-year-old voluntary worker from Braintree, Essex, who possesses no photo ID. Braintree is among 11 local authorities due to take part in the trial during local elections next May.

Labour, which opposes the voter ID plans, is backing Coughlan, and the law firm Leigh Day has been engaged to argue his case. A crowdfunding page has been launched to support the effort.

The first trials took place in five boroughs across England at the local elections in May this year, when a small number of voters were turned away.

The government argues that the change is needed to prevent voter impersonation, but critics say it is an excessive deterrent to tackle a tiny problem, and disproportionately affects more vulnerable people such as older or poorer voters, or those with a disability.

The challenge is expected to focus on arguments made by two QCs in a legal opinion last year, which said ministers acted beyond the scope of the law in ordering the trial through secondary legislation, sometimes known as Henry VIII powers, whereby laws can be amended without a vote in parliament.

Voter ID trials 'risk disenfranchising vulnerable people' Read more

Coughlan said he objected to the idea on principle. “Things are being made harder for people to vote. I would want all my neighbours to vote, but I know that some of them would struggle to produce the relevant ID. I will myself. It puts barriers where there’s no need for barriers. We should be making it easier to vote.”

Coughlan said he did not possess any photo ID. “If I was to try and get a passport it would cost me £100.”

Tessa Gregory, a solicitor at Leigh Day, said changes that could deter people from voting “ought to be subject to proper scrutiny by parliament”.

She said: “Our client believes that the minister is acting unlawfully in introducing these voter ID pilot schemes because by introducing steps which are going to make it harder for people to vote he is going beyond the powers given to it by parliament under the Representation of the People Act 2000.”

Cat Smith MP, the shadow Cabinet Office minister, said: “This legal challenge is vital for defending British democracy and Labour is throwing our support behind it.”

A Cabinet Office spokeswoman said: “We want people to have confidence that our elections are safeguarded against any threat or perception of electoral fraud.

“Electors in Braintree will be able to bring non photo ID as well as photo ID to prove who they are. Where electors have neither, locally issued ID will be made available free of charge.”