What are the arguments around the renewal of Trident which is based on the Clyde in Scotland?

• BBC Scotland's Douglas Fraser looks at how much updating the nuclear deterrent would cost.

Ms Sturgeon said she would use any clout the SNP has to stop the renewal of Trident.

Willie Rennie said there would be "absolute chaos" if the SNP hold the balance of power in Westminster.

Ms Sturgeon reiterates "the people of Scotland" will decide if there is another independence referendum.

John tweets, external: Barnett formula patriotic? Tell the Welsh that... #leadersdebate

Ms Sturgeon said that if Labour puts forward a budget that proposes cuts, the SNP would vote against it.

The BBC's Nick Robinson asks: What would hung parliament mean for Britain?

Ms Sturgeon said she was appalled when Ed Miliband said he would rule out any deals with the SNP. She said any chance to get the Conservatives out should be taken.

Nicola Sturgeon said that neither the Conservatives and Labour would win a majority, according to the polls.

Ms Sturgeon, with experience in minority governments, says parties need to work together by building support for policies.

Mr Murphy says Labour wants to change the country "dramatically".

Jim Murphy kicks off the debate on a hung parliament.

He said that if Scotland votes Labour, the United Kingdom will get a Labour government.

What is full fiscal autonomy?

• Full fiscal responsibility or autonomy would see Scotland gain complete control of taxation and spending, including most North Sea oil revenue, with Edinburgh paying London for shared services such as defence and foreign affairs.

• The IFS analysis suggests that Scotland's fiscal position will improve during the next Westminster parliament as the deficit is reduced, but that the UK's position as a whole will improve faster.

Find out more....

Mr Murphy brings up the issue of full fiscal autonomy, and says it will create a black hole in the economy.

He asks how Ms Sturgeon can talk about cutting austerity when full fiscal autonomy would result in more cuts.

Ms Sturgeon said the cuts are hurting real people who don't deserve to pay for austerity and the crash.

Ms Sturgeon said when it comes to policy, there is very little between Labour and the Conservatives.

Helen Mckay tweets, external: 15mins!! Who had money on shouting at 15mins?? #leadersdebate

Ms Davidson calls Mr Murphy a liar, to which the Scottish Labour leader responds "How dare you."

Mr Murphy said he is angry that, under a Conservative-led government, more people have had to use food banks.

Ms Davidson says changes are needed to the benefits system. The Scottish Conservative leader said they will make work pay.

She says a Conservative government will not make cuts to child benefit.