UK AI Act passes second reading — but with one amendment that changes everything

A single inserted clause on training data transparency has already enraged industry and delighted creators.

The much-anticipated UK AI Act has cleared its second reading in the Commons, but a last-minute amendment — adopted by a margin of just six votes — has fundamentally altered its scope.

The new clause requires any foundation model trained or deployed in the United Kingdom to publish a detailed, machine-readable index of all training data used, with limited exceptions.

Industry lobby groups have reacted with alarm, warning the requirement is 'commercially unworkable' and could push major AI development out of the UK altogether.

Creator and rights-holder organisations, by contrast, have welcomed the change as 'the most consequential piece of pro-creator legislation in a generation'.

The bill now heads to committee, where the clause is expected to face an intense lobbying campaign on both sides.