Labour's Lord Barnett opened a debate on changing the Barnett Formula on 15 June 2011.
Lord Barnett devised the formula over thirty years ago as a way to decide public spending levels in the nations of the UK.
It was intended to be a short-term fix but is now the established funding formula for Wales, Scotland and Northern Ireland.
Lord Barnett says the formula should be scrapped because it is too complex and unfair to taxpayers in England.
The House of Lords' Barnett Formula Committee has also said the system should no longer be used to allocate funds to the regions.
Wakles' First Minister Carwyn Jones has urged the UK government to "urgently" reform the way the Welsh government is funded from central government, after a review suggested it is short-changed by the population-based Barnett formula.
The coalition has promised its own commission to investigate whether Wales is getting a fair deal.
The SNP's Treasury spokesman Stewart Hosie has attacked the claim that Scotland benefits disproportionately from the formula as an "absolute fallacy".