London: A crowdfunding campaign has been launched to raise funds for a potential legal challenge to Theresa May’s parliamentary deal with the Democratic Unionist party, on the grounds that it breaches the Good Friday agreement.

Lawyers acting for Ciaran McClean, a Green politician in Northern Ireland, allege that the pact between the minority Conservative government and the DUP is in breach of both the landmark 1998 Northern Ireland peace deal and the Bribery Act.

The confidence and supply arrangement, signed in Downing Street on 26 June, granted £1 billion (Dh4.72 billion) more funding for hospitals, schools and roads in Northern Ireland in return for DUP support in key Commons votes.

Carwyn Jones, then the first minister of Wales, described the cash as a “straight bung to keep a weak prime minister and a faltering government in office”.

The Scottish first minister, Nicola Sturgeon, characterised it as a “grubby, shameless” deal.

McClean is represented by Dominic Chambers QC of Edwin Coe LLP. Chambers was involved in the successful Supreme Court challenge to the government’s attempts to trigger Article 50 without a Commons vote.

The legal team aim to issue High Court proceedings this week and will push for the case to be heard as early as possible. The judges, bruised by their experience over the Brexit case, are unlikely to welcome such a sensitive, political challenge but may be forced to deal with the claim. There has already been an exchange of letters over the issue between McClean’s lawyers and the government.

The basis of McClean’s claim is that any deal between the government and DUP is in breach of the 1998 Good Friday agreement, under which the government undertook to exercise its power in Northern Ireland “with rigorous impartiality on behalf of all the people in the diversity of their identities and traditions”.

The government is trying to act as an honest broker in re-establishing the collapsed power-sharing executive at Stormont. The letter from Edwin Coe argues that any agreement between the DUP and the Conservatives would compromise the government’s independence and breach the reasonable expectation of the citizens of Northern Ireland, including McClean, that the government will act with rigorous impartiality.

McClean writes on the action’s CrowdJustice webpage: “My claim is that as a citizen I expect my government to honour its obligations under the Good Friday agreement and not to bribe others with money so that it can stay in power. My lawyers have put these points to the government. They eventually responded, failing to meet deadlines they set themselves. Nothing they said addresses the fundamental issues behind this corrupt deal.”

David Greene, a senior partner at Edwin Coe, said: “This case is of huge public importance and demonstrates that individuals can call governments to account and the importance of that capability in a democracy.”

Crowdfunding is becoming an increasingly significant means of subsiding legal actions since deep cuts were introduced to legal aid in 2012. Joanna Sidhu, a former City litigation lawyer who now works for CrowdJustice, said: “Having campaigned for peace in Northern Ireland for most of his life, Ciaran McClean is bringing this legal challenge to hold the government to account. By launching a crowdfunding campaign to support this challenge, Ciaran is giving everyone the opportunity to be part of the fight to preserve our democratic values.”

The initial aim is to raise £20,000 for legal fees but more will be needed if the case progresses to a full hearing in the High Court.

CrowdJustice has so far helped individuals and organisations raise more than £3 million to fund more than 160 cases, three of which have reached the Supreme Court.