Green Party leader Caroline Lucas said today:
"I warmly congratulate Ed on his election success."
But she added:
"It's clear that Labour will need to change dramatically if it genuinely wants to be seen as a 'progressive' party.
"After 13 years of Labour Government, during which inequality increased and carbon emissions rose, it will take concerted action to persuade the public that social and environmental justice are central Labour concerns.
"Labour's ability to challenge coalition policies on everything from academies to increasing privatisation of the NHS is fatally undermined by the fact that, in all of these areas, it was Labour itself which spent the last 13 years precisely paving the way for the coalition's assault on public services."
Ed will "need to go much further if he is to demonstrate that Labour has genuinely changed"
The Brighton Pavilion MP continued:
"On issues from ambitious action to tackle climate change, support for genuine electoral reform, to the opposition to privatisation of public services, and a rigorous alternative to the coalition's savage spending cuts, it's the Green Party which is offering the real alternative, not Labour.
"So while I welcome the fact that Ed Miliband is talking about some of our long-held policies, like support for a living wage, and a high pay commission, he will need to go much further if he is to demonstrate that Labour has genuinely changed."