This week I have been lobbied heavily about the way that supermarkets can abuse their powers, and why a Groceries Code Adjudicator (GCA) is needed to police the major supermarket chains.

This is something I took up when first elected as an MP, calling on the Government to set up an ombudsman for supermarkets.

The cut throat commercial strategies of the Big Four supermarkets have serious consequences for small producers and farmers, in the UK as well as in the developing world.

But it doesn't stop there. A recent report from the Fair Pay Network, called Face the Difference, found that none of the major supermarkets have seen fit to implement living wage policies for their lowest-paid staff, although remuneration packages for top executives continue to run into millions of pounds.

So not just suppliers, but checkout staff and shelf-stackers, are being squeezed by the drive for ever cheaper food.

And whilst cheap deals can entice shoppers, consumers lose out in the long run too because the local economy suffers if small independent food retailers are put out of business.

I would like to have seen the creation of a proper supermarket ombudsman, with real power to force companies to treat suppliers and consumers fairly.

But failing that, a GCA with the power to impose fines for bad behaviour is an important first step in getting supermarkets to clean up their act.