Kate Mosse and Richard Osman have hit back at Labour’s plan to give artificial intelligence companies broad freedoms to mine artistic works for data, saying it could destroy growth in creative fields and amount to theft.

The best-selling novellists spoke out after Keir Starmer a national drive to make the UK “one of the great AI superpowers” and endorsed a 50-point action plan that included changes to how technology firms can use copyrighted text and data to train their models.

Ministers had been consulting on whether to allow the major tech companies to hoover up massive quantities of writing, music and other creative works unless copyright holders actively opt out.

It is seen as a way of supercharging the growth of AI companies in the UK. Huge volumes of data are needed to train AI models and technology firms claim copyright laws create uncertainty, which risks holding back development.

But creatives want AI companies to pay and were dismayed when the prime minister said he backed calls for a system similar to the EU, which requires copyright holders to opt out of the trawling process.

The Creative Rights in AI coalition, which includes industry groups in music, publishing, journalism, TV, cinema and photography, on Tuesday called Starmer’s position “deeply concerning” and called on ministers to continue to consider their case to keep the current copyright system.

Last month Paul McCartney warned that AI “could just take over”, and Kate Bush joined Stephen Fry and Hugh Bonneville in signing a petition warning that the “unlicensed use of creative works for training generative AI is a major, unjust threat to the livelihoods of the people behind those works, and must not be permitted”.

Mosse told the Guardian: “Using AI responsibly and well and being a world leader – all of this I agree with. It just cannot be at the expense of the creative industries … It is supporting one type of growth and destroying another part of growth. And it cannot be on the basis of theft of our work.”

Osman, who has sold more than 10m books with his Thursday Murder Club series, said: “A lot of the issues around AI are complex, but this one is very simple. If you want to use a copyrighted work, you ask permission, and then you pay for it. Anything else is theft, and anyone arguing for anything else is harming the UK creative industry.”

Monday’s AI action plan, written by the venture capitalist Matt Clifford, called for “reform the UK text and data mining regime so that it is at least as competitive as the EU … The UK is falling behind.”

EU rules require copyright holders to opt out of the trawling process. This approach is opposed by many creatives who insist they should be automatically paid for use of their material.

In its response to the action plan, the government said it will ensure a “competitive copyright regime that supports both our AI sector and the creative industries”. Starmer said: “I am happy to endorse it and take the recommendations forward.”

Jo Twist, the chief executive of the British Phonographic Industry, which represents the recorded music trade, said: “AI’s potential can be realised by growing both the creative and AI sectors, without resorting to destroying the UK’s status as a creative superpower.”

She said it was not clear “why AI firms should be allowed to plunder the creative industries, taking music for their own profit without authorisation or compensation”.

The Department for Science, Innovation and Technology has been contacted for comment.

Mosse said that five of her novels, including Labyrinth “that I spent 15 years researching, planning, writing, rewriting, editing and publishing”, have been “illegally scraped [to help train] large language models”.

She drew an analogy with a thief in a corner shop who steals all the Mars bars and when confronted by the shopkeeper says: “But you didn’t tell me you didn’t want me to steal your Mars bars.”

“That’s essentially what the opt-out is,” she said. “What is being proposed is that creators will have to spend their time hunting down AI companies to see if their work has been stolen.

“It will take time away from all of us doing the job that we do. It will mean that individuals are less likely to be able to make a living out of their craft. And consequently, everything will simply be diluted. It will be a copy of a copy of a copy of a copy. We will have very little original work.”

The AI action plan recommendation comes despite a government consultation on how copyright should be handled still has six weeks to run.

Ed Newton-Rex, a former AI executive now campaigning for AI firms to pay copyright fees, said: “It’s clear that the government has made up its mind and will upend copyright law to favour AI companies, which throws the consultation into total disarray. If this goes ahead the government will be handing the life’s work of this country’s creators to AI companies, so they can outcompete those creatives.”

A government spokesperson said: “Current uncertainty about how copyright law applies to AI is holding back the creative industries and AI sector from realising their full potential – and that cannot continue.

“That’s why we’ve launched a consultation to develop a balanced framework that works for both sectors. We’ll only move forward once we’re confident we have a practical plan that delivers each of our objectives: increased control for right holders to help them license their content, access to high-quality material to train leading AI models in the UK, and more transparency for right holders from AI developers.”