Burnham did not set out details of who would lead his proposed commission, or when it would begin its work.
Any move to change the voting system would be supported by the Liberal Democrats, who had previously urged Burnham to introduce proportional representation before the next election, which must be held by 2029.
However, any move away from first-past-the-post is likely to be resisted by the Conservatives. Reform UK backed introducing PR at the last election, but there has been speculation that its enthusiasm for the move may have since cooled.
Speaking to broadcasters after Burnham’s speech, Reform leader Nigel Farage said he was open to debating a potential change to the system “at some point” but other issues were “far more urgent”.
He added: “Is this an absolute priority for the general election after the next one? I don’t believe that it is.”
Support for changing the voting system is also not universal within Labour, with deputy leader Lucy Powell acknowledging that “parts of the Labour Party” are not in favour of it.
Speaking to Politics Live on BBC 2, she said she personally backed electoral reform but declined to specify a proposed new system, adding there were “lots of models” available.
At the last UK election the Liberal Democrats backed the introduction of a single transferable vote (STV) system, which is used for Scottish council elections.
Other options include the additional member system, a hybrid model that combines first-past-the-post with regional party lists that is used to elect members of the Scottish Parliament.
Earlier this year, the Welsh Senedd was elected for the first time using a closed-list proportional representation system.
