Lord Barnett, the peer behind the UK's regional funding formula, has called for reform of the system.

"It was never meant to go on this long, but it has... and it has become increasingly unfair to the regions of England," he said over the weekend.

"I didn't create this formula to give Scotland an advantage over the rest of the country when it comes to public funding. It is a great embarrassment to have my name attached to so unfair a system, especially as it was only going to last a year."