The Liberal Democrats have unveiled proposals to invest £150bn in green projects over three years as a way to transform the economy in the wake of the coronavirus pandemic, warning that the government must act soon on the issue.

Ed Davey, the party’s interim leader, said there was “a once-in-a-lifetime opportunity” to both tackle potential mass unemployment due to Covid-19, and reshape the economy on more environmental lines.

Labour has also announced ideas to rebuild the economy with measures such as training young people to work in green industries.

Davey said Boris Johnson appeared to have not yet grasped the urgency of the situation.

“You’ve got to have a very high level of ambition, and the way the government is talking about it, I’m not yet convinced their level of ambition is high enough,” he said. “With Johnson I think he may focus on some of the projects that get good headlines but not the ones we really need.”

Davey’s proposals would involve investing £150bn in the green economy over the next three years, part of a total £350bn post-coronavirus rescue package.

Specific ideas include a so-called green jobs guarantee, giving people training in new, environmental industries such as renewable energy, insulating homes and rewilding projects, paid at least the national living wage. Another pledge would be for at least 80% of energy to be from renewable sources by 2030.

“If unemployment is going up anywhere near what people are saying, this is going to be absolutely essential,” Davey said.

“There’s a once-in-a-lifetime opportunity to solve the massive crisis we’re in.”

Properly insulating homes was vital for meeting existing green targets, Davey said, and could rapidly create jobs, with many local authority projects renovating social housing ready to go ahead. This would create jobs in supply chains, and help with those most affected by fuel poverty, he said: “So there’s a big social win there too.”

For rewilding programmes, people could work on areas such as tree-planting and peat bog restoration.

Other areas of the plan include a requirement for at least half of all Bank of England financing to go into green investment programmes, and a new system of government “climate bonds” to raise extra capital. People would also receive tax incentives on savings and pensions for investing in green areas.

Labour has unveiled similarly ambitious plans, with the shadow business secretary, Ed Miliband, calling for the creation of a “zero-carbon army of young people” doing work such as planting trees, insulating buildings and working on green technologies.

Miliband has likened the task to the rebuilding process undertaken by Clement Attlee’s postwar Labour government, which involved the creation of the NHS.

Guest post from The Guardian