The former work and pensions secretary has met with senior figures at a number of major London PR agencies in recent weeks.
Well-placed sources suggested that Purnell was looking for a six-figure salary and a mix of lobbying and corporate PR.
‘He's been talking to a lot of people,' said one agency boss.
Purnell, previously a pivotal figure in the Blairite wing of the parliamentary Labour party, recently stood down as an MP after nine years in the Commons. He is a close friend of Labour leadership contender David Miliband and of Tim Allan, founder of public affairs firm Portland.
Purnell's Twitter biography states: ‘No longer the MP for Stalybridge and Hyde, working out what to do next...'
More than 100 MPs stood down at the 2010 election. If Purnell does sign up with a PR agency, he will not be the first of the ex-MPs to do so – but he would become the first of the Labour contingent to secure such a role.
Earlier this year, former Tory MP Andrew MacKay joined the lobbying arm of Burson-Marsteller, having stood down at the general election. He was recently followed into lobbying by his wife Julie Kirkbride, also a former Tory MP, who has taken a job with the public affairs firm Tetra Strategy.
Purnell could not be reached for comment