The Green Party will pledge to raise taxes for the wealthiest in society and mend “broken Britain” in its election manifesto.

A tax on multimillionaires and billionaires will be used to fund improvements to health, housing, transport and the green economy, the party said.

Ahead of the manifesto launch in Brighton and Hove, Green Party co-leader Adrian Ramsay said the party intends to change the “conspiracy of silence” on taxes by creating a fairer system and asking those “with the broadest shoulders to pay more”.

A programme called the Green Economic Transition has been put forward to upgrade homes across the UK to increase their energy efficiency, which the party said will make them warmer and cheaper to run.

The party has previously promised to spend £50 billion per year on health and social care by 2030 and has now committed to protect the climate for future generations and “bring nature back to life”.

Sian Berry, who is seeking to succeed Caroline Lucas in Brighton Pavilion as the party’s only MP, said that “the time for half measures and empty promises is over”.

And Mr Ramsay said: “There is a conspiracy of silence between the main Westminster parties at this election.

“Labour and the Conservatives would rather hide their plans for cuts to public services than confront the need for a fairer tax system that asks those with the broadest shoulders to pay more – including the very wealthiest in society, who have grown even wealthier over the last 14 years.

“If people are to have access to an NHS dentist or a GP appointment, if we are to create warm, secure homes for all and fund the green transition to tackle the climate crisis and create the jobs of tomorrow, we must be honest today.”

He added: “By asking those with the broadest shoulders to pay more – including the very wealthiest – we can invest in the frontline services and infrastructure that we all rely on.

“With more Green MPs in Parliament, we will stop Labour backtracking on any more of their promises.

“We will push them to be braver, to be more ambitious, and to actually do what’s necessary to fix our broken country and get us back on track.”

Co-leader Carla Denyer said: “Things can only get worse under Labour unless we dramatically change our tax system to raise money from those with the broadest shoulders.

“Young people, in particular, know just how broken Britain’s frontline services are. The economy is not working for them. They have been priced out of the housing market and are struggling to fund their education.

“Now is the moment to be ambitious – not unrealistic, but ambitious.

“To be clear about the kind of country we want to live in. About how broken our public services are and the action that’s needed to fix them.”