The Scottish National Party and Plaid Cymru are calling for a 'progressive alliance' government for Britain, involving themselves, Labour and the Liberal Democrats.

A senior Liberal Democrat has said his party may choose to scrap all the UK's nuclear weapons, suggesting a different emphasis to party leader Nick Clegg's focus on a cheaper alternative to Trident.

Plaid Cymru and the SNP have said they offer the only “real alternative” on nuclear arms, pointing out that the Liberal Democrats would replace Trident with a different nuclear system.

Plaid Cymru's election candidates have signed a pledge promising to stand up for the needs of pensioners. They said that a “living pension” is needed more than a nuclear weapons system.