Labour “knows the price of everything and the value of nothing”, the Green Party’s co-leader has said in a conference speech urging the Government to be “more ambitious”.

Adrian Ramsay used his address on the opening day of the Green Party conference in Manchester to launch a wide-ranging attack on the Government, saying it was not doing enough on the NHS, housing or the climate crisis.

Taking the stage alone on Friday after his co-leader Carla Denyer developed Covid-like symptoms, Mr Ramsay said Labour had “an obsession with growth at any cost”.

He added: “They really are becoming the party that knows the price of everything and the value of nothing.”

Promising to hold the Government to account “where we think greater ambition is needed”, he said: “Because in so many areas, ones that matter deeply to so many of us, Labour is getting it wrong.

“Like denying winter fuel payments to millions of pensioners, giving the green light to new climate-destroying airport expansion, and to sticking with the cruelty of the two-child benefit cap.

“Like the welcome but half-hearted, partial suspension of arms sales to Israel, and continuing with the nonsensical ban on asylum seekers being allowed work.

“So conference, we will be using our voices in Parliament to raise up the voices of the two million Green voters who want so much better.”

The conference comes two months after the Green Party’s most successful UK election yet, in which it quadrupled its number of MPs and came second in 40 constituencies.

In all but one of those seats, the party came second to Labour, suggesting the path to further Green success lies in a battle with Sir Keir Starmer’s party.

We need to invest in defending public services and protecting our environment – and we can do so with some changes to the tax system to ask the wealthiest in society to pay a little more

Criticising Labour’s plans to use more private sector healthcare to tackle NHS waiting lists, Mr Ramsay said the Government “lack the ambition and vision to do things differently” and reiterated his party’s call for a wealth tax.

He said: “We need to invest in defending public services and protecting our environment – and we can do so with some changes to the tax system to ask the wealthiest in society to pay a little more.”

While he welcomed the new Government’s commitment not to issue new oil and gas licences, Mr Ramsay urged ministers to block the new Rosebank oil field approved by their predecessors, saying there was “no justification” for its development.

He said: “The science is super clear, there must be no new oil and gas.

“This is a non-negotiable and you can be sure that as a Green MP I will do everything I can to fight for a safe climate.”

Mr Ramsay also used his speech to call for water companies to be renationalised and criticised Labour’s housing policy as lacking an incentive to build affordable homes.

The Green Party conference is set to continue over the weekend and see the party urge Chancellor Rachel Reeves to adopt a series of tax reforms and rises at the Budget aimed at increasing health spending, carrying out social care reform, and embarking on a nationwide home insulation programme.

Among the tax hikes the Greens propose are a wealth tax on billionaires and multi-millionaires, reforms of capital gains tax and inheritance tax, and closing loopholes in the windfall tax on fossil fuel producers.