John Swinney has defended comments he made about proposed changes to the UK state pension amid claims he may have misled parliament.

After Andy Burnham announced potential reforms to the "triple lock", the first minister told MSPs that "we are now going to lose our pensions".

Scottish Conservative leader Russell Findlay said this was an "inaccurate and irresponsible" comment which could cause concern to pensioners.

Swinney has now written to Findlay defending the remarks - adding that the independent advisers who oversee the ministerial code could initiate an investigation should they wish.

The "triple lock" was introduced in 2011 as a guarantee that the UK state pension would rise each year in line with whichever is the highest of inflation, average wages, or 2.5%.

In his Labour conference speech, Burnham said he would look to "adjust" this rule from April 2030 - after the next general election.

He said pensions would rise in line with the highest of inflation or 2.5%, and added that it would "hold its value relative to earnings over time".

The UK government says this would reduce projected spending on pensions by £15bn a year by the end of the 2030s, rising to £50bn a year by 2050.

Burnham said this would provide funding to deliver a new National Care Service in England from 2030.

The state pension operates UK-wide. In Scotland about 1.1m people are in receipt of it, a figure which is projected to rise to 1.4m by 2047.

However social care is devolved in Scotland, and a system of free personal care was introduced way back in 2002.

Swinney says this means Scottish pensioners would be affected by the changes to the triple lock, but would not benefit from the proposed care changes.

He said the move would "take up to £4bn from Scotland's pensioners" by 2050, adding that "this would mean in real terms every pensioner in Scotland being almost £2,000 worse off in 2050".

The UK government says it does not recognise these figures, which have been calculated by working out Scotland's share of the pension-age population, compared with the projected saving from the changes.

On Thursday, Swinney was challenged about his social media post in the Holyrood chamber by Scottish Labour leader Michael Marra, who accused the first minister of "misrepresenting the position of the UK government on social care reform".

And in a subsequent exchange with Scottish Tory leader Russell Findlay, Swinney stated that "we are now going to lose our pensions", saying this made the case for Scottish independence.

Findlay - who oddly enough agrees with Swinney about preserving the triple lock - wrote to him saying that "this inaccurate and irresponsible comment is inevitably causing concern to Scottish pensioners", calling for him to correct the record.

But in interviews on Monday the first minister insisted: "I stand by everything I said to parliament".

He then wrote to Findlay to explain how he believed there would be a "real terms" reduction in pensions "as compared to the existing triple lock policy".

Swinney added: "I am satisfied that no correction to the parliamentary record is necessary."

Swinney has flagged up the row to his independent advisers, who can decide to investigate potential breaches of the ministerial code.

They could recommend action, such as a statement to parliament.

Swinney would ultimately have the final say on whether there had been a breach, and it would be up to him to decide what action, if any, was required.

There have been such probes before. Nicola Sturgeon and Alex Salmond were both cleared of misleading parliament by independent advisers.

Earlier this year Angela Constance was found to have breached the code, but was just given a telling-off after the advisers concluded it was an inadvertent slip.

On Tuesday, Swinney brought up the issue in parliament again, when a helpful question from one of his backbenchers allowed him to offer a rather more carefully phrased version of his attack.

The rather blunt phrasing about how "we are going to lose our pensions" was replaced by a formulation stressing that any loss was "compared with the current triple lock being maintained".

Should the advisers look into the matter, Swinney may point to that as his attempt to correct the parliamentary record at the earliest convenience, as the ministerial code requires.

There are two points here.

One is to stress that pensions would continue to rise under the proposed new system, just potentially not as fast as they would under the triple lock.

Pensions would not be cut from their present level - and nobody would "lose" their pension altogether - but they might not have gone up by as much as they would have done had the triple lock remained in place.

The other point is that if the money raised is spent on social care in England, as Burnham has suggested, money would actually flow back into Holyrood's budget.

This is because of the way devolution works. Various powers over issues including health, education, justice and, yes, social care are the responsibility of the Scottish Parliament.

When money is spent on those portfolios at a UK level, Holyrood is given a population-adjusted share of that sum, which MSPs can allocate as they see fit.

So any changes which increase spending on a devolved issue at Westminster will increase the "block grant" which goes to Holyrood.

For example, earlier this year the UK government announced billions of pounds in extra funding for school pupils with extra support needs.

Education is devolved, so this triggered extra payments to Holyrood - £533m in the current year according to the autumn budget revision, which was chiefly spent on the NHS.

So if extra funding was raised from pension changes and the direct result of this was increased spending on social care in England, that should trigger an increase in Holyrood's block grant.

The Scottish government would be free to spend that money on pensioners - it has the power to top up benefits or set up new ones, and indeed does so with things like pension-age winter fuel payments.

It would be a slightly different issue if the money was spent on something like defence, which is fully controlled at Westminster. In that case there would be no increase in Holyrood's funding.

Swinney has insisted that "none of us can foresee what the implications of these changes would be for the block grant".

But it is generally difficult to forecast what will be happening in the year 2039 or 2050.

It is difficult to forecast what earnings or inflation might be, and what that would mean for pensions.

And it is difficult to predict what the state of devolved finances would be - indeed Swinney hopes Scotland will be independent by then.

If the 2014 campaign is anything to go by, then these kinds of debates about pensions could be instrumental in whether that happens or not.