Ian Paisley yesterday dismissed pressure over his son's political problems and a report that he plans to step down as Northern Ireland First Minister, during a visit to Edinburgh.

The Stormont leader and veteran Democratic Unionist chief refused to comment on either subject, preferring to joke about them after his talks with Scottish First Minister Alex Salmond.

His four-member ministerial team visiting the Scottish capital included Ian Paisley Junior, who quit his ministerial post on Monday over his links with a property developer in the province, but remains in office until a replacement is appointed.

The report of the his plans to stand down is another factor putting Dr Paisley on the back foot as he met his Scottish opposite number to discuss transport, energy and education.

He tried not to comment, but could not resist a sharp response to the Northern Irish journalists travelling with him. Asked about his son's difficulties, he told one: "I have a fairly hard rhinoceros skin - and I think I will not be skinned by you or the likes of you."

And asked by another about the media report of resigning, he said: "I've no comment whatsoever. It's a wonder they didn't tell you I was dying of all sorts of diseases and that soon I would be carried out in a box. That's usually added to make it more spicy."

Dr Paisley was visiting Edinburgh with his Sinn Fein deputy, Martin McGuinness. They toured Holyrood, and then held talks with Mr Salmond and other Scottish Government ministers in Edinburgh Castle.

At a press conference, Dr Paisley shared a platform with two men whose political creed is to break up the United Kingdom.

Asked about his differences with Mr Salmond, the Unionist reminded the SNP leader he had sworn a solemn oath as a Privy Counsellor, adding: "I believe Alex is as loyal as I am." The Sinn Fein Deputy First Minister said their meeting represented "a little bit of history".

The day's events continued with lunch at South Queensferry's Orocco Pier restaurant, where the visitors learned about plans and designs for the new Forth crossing, before going to Murrayfield Stadium in the capital, where they met young people working on an anti-sectarianism project.

After having pictures taken with the youngsters, Dr Paisley departed without seeing the project itself.

In their bi-lateral talks, the Scottish and Northern Irish ministerial teams agreed to a feasibility study, to be ready this summer, aimed at bringing back the Ballycastle-Campbeltown ferry, which failed to meet commercial targets when it was tried eight years ago.

Asked what the ferry should be called, Dr Paisley said he had an idea, but was unwilling to make it public as it might be seen as sectarian.

The two sides also agreed a joint approach to the European Commission to access funds for a study of the case for a sub-sea electricity inter- connector across the North Channel. This is intended to boost the case for renewable energy in Scotland and in the province.

There were discussions about developments of ferry terminals that link Scotland to Northern Ireland, which along with the A75 Dumfries-Stranraer road, are a vital commercial link for the province. They also discussed a joint approach to the Treasury over rural fuel costs.

Dr Paisley also highlighted the talks had covered the topic of student finance, which has been a source of tension between Holyrood and Stormont, since the Scottish Government axed any contribution to tuition fees, leaving the many Ulster students at Scottish campuses at a disadvantage. The two sides continue to look for ways to resolve their differences on that.

Asked about US tycoon Donald Trump playing off Scotland against Northern Ireland over the site of a major golf resort investment, harmony broke out between the two teams with Mr Salmond saying the Ulster leaders were doing their job in promoting economic growth.

The Scottish First Minister has agreed to attend a major conference in Northern Ireland this spring to discuss the economy with prospective investors.

Mr Salmond said his administration was "cheering from the sidelines" with the re-establishment of devolution last year in Northern Ireland.