The Green Party has taken aim at Labour's "timid" plan for government as it launched its general election campaign.
Only a strong Green presence can "push" Labour to be bolder on climate, the NHS, and housing, party co-leader Carla Denyer said.
The party said the Conservatives were "clearly on their way out", so would focus their campaign on challenging Labour.
After record local election gains, the Greens aim to secure four MPs for the first time in their "most ambitious" campaign yet.
The Greens plan to field candidates in every constituency in England and Wales for the 4 July election. But the party will focus their efforts on four seats they see as winnable.
The Scottish Greens are separate party, who will field candidates in Scotland.
The Green Party of England and Wales kicked off its election campaign in Bristol, where the Greens now lead the council after winning 10 new seats at the 2024 local elections.
Ms Denyer, who is the party's candidate for Bristol Central, said: "The case for change is obvious, but it has to be real change that offers real hope. Half measures and broken pledges will not do.
"The Conservatives are clearly on their way out of government, but Labour is failing to offer the real change needed.
"Across the country, people now have the chance to vote for real hope and real change."
Co-leader Adrian Ramsay, standing in the new Waveney Valley constituency in an area which has traditionally voted Conservative, said: "Over the past five years, we have increased the number of councillors five-fold.
"After so much damage by the outgoing Conservative government, we need Green MPs to ensure the next government takes the bold actions necessary for real change."
Ex-London Assembly member Sian Berry is hoping to replace long-standing Green MP Caroline Lucas as the representative for Brighton Pavilion.
The party is also focussing on the fight in North Herefordshire, where former Green Party MEP Ellie Chowns is standing.
The Green Party proposing to build 150,000 new council homes and ending the Right to Buy.
They also aim to reverse NHS privatisation and introduce a Nature Act to "protect and restore the natural world".
If elected, they would also seek to reform Nato and commit to no first use of nuclear weapons.
A full list of parliamentary candidates for all constituencies will be available on the BBC news website when nominations have closed.