A legal opinion by the law firm Leigh Day, commissioned by the Campaign for Nuclear Disarmament, says there are serious grounds to question whether Britain is facilitating unlawful military action by letting US forces use UK bases, the Morning Star reports.
According to the paper, the opinion finds "significant questions" over whether Britain breaches international law by relying on US claims of collective self-defence. It argues that because the US is the aggressor, operations justified as collective self-defence are likely to fail the necessity test.
Tessa Gregory, Leigh Day's head of human rights, is quoted as saying:
"Calling a strike 'defensive' does not make it lawful."
She added: "Our advice raises serious questions about the government's justification for allowing US forces to use UK bases." The firm says there is "very little public information" about how targets are selected and what intelligence is relied on.
The Morning Star says Sir Keir Starmer, then prime minister, allowed "limited" use of British bases for "defensive" operations after the March strikes. Unions including Unison are calling for the UK to end its involvement, and the paper says the TUC has repeatedly called the war illegal.
The Morning Star's report carries no response from the UK government.