RETIREMENT planning has been thrown into chaos after UK ministers admitted they don't know how many Scots will qualify for the full flat-rate pension.

Experts have called on the government to write to citizens who aren't eligible for the new £155-a-week pension, to advise them to plan ahead.

But the Department for Work and Pensions (DWP) has conceded it does not know how many will be affected north of the Border this year.

Read more: Women bear the brunt of our pensions shortfall

In March a committee of MPs warned that across the UK more than half of new pensioners would fail to qualify in 2016-17.

Scotland is already facing a pensions crisis after it emerged that millions of Scots are not saving enough for their retirement.

Shadow Scottish Secretary Ian Murray said: "We know that many of us need to save more, but in order to know how much to save, we need to have a good idea of what we are entitled to.

The Herald:

"The Government have a duty to ensure that people have all the information they need in order to plan for their retirement."

The new flat-rate state pension was announced with great fanfare by David Cameron.

It was finally introduced last month at £155.65 a week.

But even the Tory pensions minister Ros Altmann has suggested that the new scheme has been missold.

Read more: Public 'still very much in the dark' about pension reforms

“Where things have gone wrong is that everybody thinks it is a flat rate £155, £156 or whatever," she said earlier this year.

"The flat-rate bit is the build-up, so every year in the new system you are building up [to] a flat-rate amount.’

MPs on the House of Commons Work and Pensions Select Committee found that across the UK just 13 per cent of people reaching state pension age this year will receive the full amount.

Almost a third, 32 per cent, will receive more because they have built up additional state pensions.

The Herald:

But UK-wide more than half, 55 per cent, will receive less than £155.65 per week.

Many will lose out because they have not worked for long enough or are women whose pension is based on their spouse’s contributions and are not covered by transitional arrangements.

Ministers say that over time the proportion of new pensioners across the UK who qualify for the full amount will rise.

But by 2020 almost half would still not receive the total amount.

Read more: Public sector pension five times more valuable than private version

Experts told MPs that the impression that the system was “very good and more generous for everybody" risked “effective retirement planning".

The DWP says that it has launched an awareness campaign.

But MPs called on ministers to directly contact those affected and others with gaps in their contribution records.

A DWP spokesman said: “We are committed to ensuring that people fully understand the changes being made to the State Pension, that is why we launched a multimedia campaign in 2014, which will continue over the coming months and years.”

He added that the new state pension was designed to create a system that was simpler and easier to understand.

He said that millions stood to gain from the changes, including women and the self-employed.

Asked what proportion of people in Scotland who reach state pension age in 2016-17 will receive less than the full flat rate of the new state pension, Work and Pensions minister Justin Tomlinson said: "The Department cannot model the impact of the new state pension at a regional or country specific level."

Earlier this year former Work and Pensions Secretary Iain Duncan Smith suggested that the state pension age could be lowered in Scotland.

Mr Duncan Smith said that there were "legitimate questions" about how the national age of retirement affected those who die earlier.

He had been asked by SNP MP Eilidh Whiteford what his department would do to protect Scots who die younger than other Britons.