Dundee East MP Stewart Hosie and Transport and veterans minister Keith Brown have launched rival bids for the deputy leadership of the SNP.
Mr Hosie, who is the SNP Treasury spokesman at Westminster, said his aim would be to return the largest-ever number of independence-supporting MPs to Westminster.
Mr Brown, the MSP for Clackmannanshire and Dunblane, pledged to move the party and the country forward in the wake of the independence referendum defeat.
Mr Hosie, who is the SNP Treasury spokesman at Westminster, said his aim would be to return the largest-ever number of independence-supporting MPs to Westminster.
Nicola Sturgeon stood down as SNP deputy leader as she declared herself as a candidate to succeed Alex Salmond as both leader and first minister.
Her successor will be decided by a vote from party members.
Launching his campaign in Dundee, Mr Hosie said the “incredible energy and enthusiasm” of the Yes campaign must be maintained to ensure that the new powers promised for the Scottish Parliament are delivered.
He said: “It will be vital to keep the energy of the Yes movement alive as we continue to campaign for more powers. The next opportunity we have to do that is the 2015 general election.
“But let me be clear – I do not believe that election should be a re-run of the referendum.
“Rather it is Scotland’s chance to hold Westminster to account – to hold their feet to the fire – ensuring that they keep their promise to deliver devo-max – maximum devolution – and that means devolving everything apart from defence and foreign affairs.
“Let us be clear: it was that promise – of devo-max – which encouraged large numbers of Scots to vote No in the referendum.”
Mr Hosie said the SNP must now reach out to those who voted No in the referendum.
He added: The best way to do that – to make sure Westminster delivers – will be to return the largest-ever number of independence-supporting MPs to Westminster.
“I believe I can play a leadership role in that campaign and beyond.”
Mr Brown, a former marine, said he was putting himself forward for the role after more than half the MSPs at Holyrood asked him to do so.
He insisted his desire for Scotland to be independent was “as strong as when I joined the party 30 years ago this month” but said a referendum was the only way to achieve that and refused to give a time when another such ballot could be held – a stance which mirrors Ms Sturgeon’s position.
Mr Brown told a press conference in Edinburgh: “Any further attempt to ask the people to support independence has to be through the ballot box and through a referendum.”
But he added that “in terms of putting a time limit, you can’t do that, it really does depend on circumstances and the people”.
Mr Brown said that by standing for deputy leader – which would then pave the way for him to become deputy first minister – he wanted to help the “rapidly-growing” party achieve its two main goals of independence and furthering the interests of the Scottish people.
Following the promise made by the three main Westminster parties of further devolution, he stressed: “Those interests must include the maximisation of the powers we need to address the pressing needs of the people of Scotland for jobs, for greater equality, and for greater life chances, generally for greater social justice.”
He went on: “I also wish to help those 36,000-plus new members and of course the 25,000 or so existing members come together so they can all play a full and active part.
“It really is about building a political party which reflects the interests of now more than 60,000 members.”
He also stressed he had worked closely with Ms Sturgeon, adding: “I believe that’s a very good relationship and can serve the party well.”