The former minister who gave his name to the funding mechanism for Scotland, Wales and Northern Ireland has said it is "vital" for the future of the country that it is reformed.
Labour's Lord Barnett, who invented the Barnett formula when he was Chief Secretary to the Treasury in the 1970s, said he had not expected the mechanism to last for three years let alone 30.
He made his comments on 11 March 2010 in a debate on a select committee report on the formula which recommends it is replaced with a new system based on an assessment of "explicit needs".
"If we don't do something about it soon the only people who will benefit from this are the people who want to break up the UK like the SNP in Scotland," Lord Barnett said.
"I hope whoever is in power after the next election they will implement the recommendations of this report - it is vital for this country."
Lord Barnett said it was not a tribute to the formula that it has lasted so long. "It is a tribute to the fact that governments of all persuasions don't like to make the major changes that are needed," he said. "It is not just New Labour it is everyone else as well."
He said it had only become known as the Barnett formula after the Conservative government kept it going for 18 years.
"When I published my book in 1982, called Inside the Treasury, I never even referred to the formula because I never thought it would last that long."