Former prime minister Gordon Brown has said Labour can only deliver on its principles in power as he made a high-profile intervention in the leadership contest with a keynote speech.
Mr Brown said he did not aim to attack any of the candidates in a speech that set out to clearly distance himself from support for frontrunner Jeremy Corbyn.
Gordon Brown will make a high-profile intervention in the Labour leadership contest with a keynote speech at London's Southbank Centre.
While he is not expected to endorse any of the four candidates in the race, Mr Brown's address is expected to distance himself from the policies of front-runner Jeremy Corbyn.
The speech on "power for a purpose" is expected to call for Labour to realign itself on the economy.
Mr Brown's intervention comes after several public attempts by his predecessor in power Tony Blair to warn against a Corbyn victory.
Former PM avoided naming any Labour leadership candidates in his speech, but appeared to make a veiled warning against electing Corbyn.
A poll rates Jeremy Corbyn as the leadership candidate both most likely to improve Labour's fortunes and damage the party's chances.