CANDIDATES at the General Election should expect to justify their position on renewing trident nuclear weapons, according to the SNP's defence spokesman.

The SNP led a debate in the House of Commons on the plans to renew the Trident nuclear missile system, branding it a waste of money.

Angus Robertson SNP defence spokesman said the government's plan showed the austerity agenda did not include Trident.

The SNP had criticised several Labour Scottish MPs for not taking part in the debate and said voters will want to know their position.

He said the UK Government was pledging more cash to the project which will be decided by Parliament next year.

Mr Robertson said: "MPs can be expected to be asked by the electorate how they will vote on Trident in 2016.

"The time has come to put down a marker about scrapping Trident and not replace these weapons of mass destruction."

He said the next generation of nuclear weapons would be eight times more powerful than the atomic bomb dropped on Nagasaki in Japan at the end of the Second World War.

Mr Robertson added: "I have yet to hear from Trident supporters in which circumstances they would be prepared to justify the killing of millions of people."

The opposition Day Motion to scrap Trident was supported by Plaid Cymru and the Green Party.

Caroline Lucas Green MP said nuclear weapons were "useless and irrelevant".

Central Ayrshire Labour MP, Brian Donohoe, said it was "crazy" not to have a nuclear deterrent and suggested there had been submarines entering Scottish Waters from other, non Nato, countries.

He said: "When there are submarines coming up the Clyde from Russia he's telling us we shouldn't have a deterrent. It's a crazy notion."

Angus MacNeil, SNP MSP said if there were Russian submarines coming "up the Clyde" it showed the nuclear deterrent "was not working".