The Rugby Paper can reveal that the Exiles will this season receive a total of around £1.5m while others will receive more than £4m.
The next lowest payment in the Premiership is, surprisingly, the £3m received by champions Northampton.
The payments reflect the unbroken time clubs have spent in the top tier, plus ‘P’ shares from being original members of the league, and Academy payments.
But a Championship source said: “What chance do promoted teams have of competing on anything like a level playing field with this kind of imbalance?
“Unless it changes we understand London Welsh are seriously considering a legal challenge against PRL.”
The inequality is underlined by the system in France where teams promoted from the Pro D2 are not only given the same level of funding as their Top 14 rivals, they are handed an extra €400,000 to enable them to buy players.
Aviva Premiership payments for July 1 – Sept 1 2014
More than £1m: Gloucester, Newcastle, London Irish andSale
Circa £900,000: Wasps, Exeter
Between £820-£880,000: Harlequins, Leicester, Saracens and Bath
Circa £770,000: Northampton
Circa; £350,000: London Welsh
Outside Premiership
Circa £900,000: Worcester
Circa: £650,000: Bristol
NICK CAIN