ALEX Salmond has said he has no intention of going "on and on" in politics – on the day he became Scotland's longest-serving First Minister.

He stressed he had no immediate plans to depart the scene with the independence referendum due in 2014. But he ducked questions about his future if voters reject his bid to take Scotland out of the UK.

In a series of interviews marking his 2002nd day as First Minister – overtaking his predecessor Lord McConnell – Mr Salmond said: "I know you must not repeat the mistake of some politicians and say you'll go on and on. I won't say that.

"I want to see Scotland win the referendum, I want to see the opening of the door of opportunity in that referendum, and I have no immediate plans to depart the scene."

His comments were in deliberate contrast to Margaret Thatcher's famous claim, after her third election victory in 1987, that she planned to go on and on.

However, he refused to say whether he would quit if he lost the referendum, telling the BBC: "If there's a choice, let's win it."

The First Minister said his toughest time in office followed the decision to release Abdelbaset Ali Mohmed al Megrahi, the man convicted of the Lockerbie bombing, on compassionate grounds in 2009 – a move which sparked outrage in Britain and the US. But he insisted the decision had not damaged his Government because people understood it was taken "for the right reasons".

He played down the storm over an independent Scotland's EU membership, which has engulfed the Government in recent days, claiming: "In the league table of stooshiness the last couple of weeks is pretty minor compared to Megrahi."

Mr Salmond said his political high point was the 2011 election, when the SNP secured an unprecedented outright majority at Holyrood. His biggest achievement in Government, he said, was to protect and extend the "social contract" of free services and entitlements, including university tuition and prescription charges.

He said: "These are big social protections and advances, and that is what I would describe as a social contract between the Government and the people."

The claim was seen as a challenge to Scots Labour leader Johann Lamont, who questioned the fairness and affordability of Government giveaways.

Mr Salmond spoke out during a day of engagements to mark the milestone of becoming the longest serving of Scotland's four first ministers to date.

Earlier, he addressed an ethics conference organised by the Church of Scotland in Edinburgh, delivered a cake to mark a Glasgow school's birthday and visited Commonwealth Games facilities in the city to announce a sponsorship deal.

He told the church conference that an independent Scotland would remove nuclear weapons.

He said: "You don't have to be a big country to have a big vision. You don't need Trident missiles to get people to listen to you, if you have something to say. As an independent nation, we should seek to have influence as opposed to state power."

The Scottish Government insisted it was a normal working day for Mr Salmond.

A spokesman added: "Becoming the nation's longest-serving First Minister is a significant milestone, but the focus remains on looking forward to the challenges and great opportunities which lie ahead."

Scots Tory deputy leader Jackson Carlaw joked: "Only [Mr Salmond's] own modesty is denying the public a balcony appearance along with a new range of mugs and tea towels."