These subsidies involved in brit proposal aren't threaten in near term and France could continue paying them, instead of EU paying for them.

Basically the brits are willing to give up what's called a Rebate, but only if in somewhere around 2014, these French farmers subsidy is phased out of EU budget. Which means the Brits in the short term are going to subsidize French farmers. The brits are willing to do this because they favor EU enlargement, and also because it's a bit silly supporting these farming subsidizes and dumping money into Africia- because these subsidize are major factor in contributing to Africa's continued poverty.