Last month, I paid a visit to one of the increasing number of food banks in Scotland.

The volunteers at our food banks and soup kitchens across the country provide an invaluable lifeline to hundreds of people right across the country. But the very fact that they exist is a stain on our society.

It is absolutely unacceptable that anyone in a country as prosperous as Scotland should have to rely on food banks.

The Scottish Government recently provided an additional £9.2 million to the Scottish Welfare Fund.

This means that local authorities have the capacity to award an extra 5600 community care grants and more than 100,000 crisis grants this year to help those who need it the most. But the reason that so many families find themselves in need of such support is clear.

Scottish Government research has found that all the food bank providers pointed to welfare reform, benefit delays, benefit sanctions and falling incomes as the main factors driving this increase in demand.

The scale of food-aid provision across the UK has increased exponentially in recent years. A recent report compiled by Oxfam and Church Action on Poverty estimated that more than half a million people in the UK are now relying on food aid .

There are now more than 100 food banks operating across Scotland. In a country as wealthy as Scotland, that is a disgrace.

In 2009, there was one food bank operated in Scotland by The Trussell Trust, the organisation in the vanguard of food banks, yet by October 2013, the number it was running had increased to 42 in operation and 17 in development.

Trust data from its food banks around Scotland shows that they have experienced a substantial increase since April 2011 in the number of people receiving food aid.

Research from the Office for National Statistics shows that there has been a fall in real terms incomes at the same time as a large rise in food prices in the UK.

And the rise in food prices adversely and disproportionately affects low income households.

The Trussell Trust has also conducted research into the use of food aid and found that, for the first time, benefit changes have superseded low income as the second most important reason for referrals.

And both formal and informal food-aid providers agree that welfare reform and changes in benefits are driving the increase in the demand for food aid.

The UK is already one of the most unequal societies in the developed world, and the UK Government's welfare cuts programme impacts unfairly on some of the most vulnerable members of our society.

I urge the UK Government to publish their long-delayed research into the growth of food banks now, to illustrate the impact of its welfare reforms.

The number of families forced into this situation is shameful. UK ministers need to account for the impacts of their welfare decisions.

We are doing as much as we can under the restricted powers we have. Last week, we announced that we are to introduce free school meals for all pupils in primaries one to three.

As part of a £114 million package for young people over two years, every one of Scotland's P1 to P3 children will have the option of a free meal in school from January next year, improving health and wellbeing, increasing attainment and saving families at least £330 a year for each child.

From this August, we will also provide 600 hours of free childcare for an additional 8400 two-year-olds from families where no-one is in work. We are investing £3.5m to create 2000 new jobs in the childcare sector to cope with the increased numbers of children. By August 2015, the overall level of free learning and care being delivered for two-, three- and four-year-olds in Scotland will exceed that which is promised elsewhere in the UK.

This childcare will allow mothers to go out to work and earn money to help their families. Recent revelations suggest that more around one-third of the current childcare promise in England is not being delivered due to a lack of preparation and capacity. In Scotland, we will both prepare and deliver.

And from next year, a further 7000 youngsters will be entitled to the same level of childcare - bringing the total to 27% of all two-year-olds.

If Scotland were to become independent, we would have full control of the welfare system, and would be able to do much more.

Only then would Scotland have the powers needed to guarantee that our most vulnerable families and groups are protected."