Labour leader Sir Keir Starmer is to promise “the biggest ever transfer of power from Westminster to the British people” if his party wins the next election.
He will launch a report in Leeds on Monday that proposes far-reaching reforms to the UK’s political system.
The report will recommend abolishing the House of Lords, despite some peers warning against this.
Sir Keir told the Sunday Times the changes could take more than one term.
But Sir Keir told the newspaper the report – which he commissioned in 2020 and was overseen by former Labour Prime Minister Gordon Brown – was not “intended to sit on a shelf”.
The Labour leader said it was “an important report” which “we will now consult about implementing”.
He will set out the recommendations in the report, titled A New Britain, alongside Mr Brown on Monday.
The report will put forward 40 recommendations, including proposals for handing new economic powers to English mayors, local authorities and devolved governments.