BA Pilots work to bidline rules which are industrial agreements and limits much like the cabin crew work to their industrial agreements. As dave747436 says pilots can work to scheme should the need arise on the day and be willing.
Much that we could kick and fight our way through and say we wont accept any changes to our agreements, should every other competitor be working their crews to EASA limits then it is a futile fight. The worst case scenario is we win and make BA uncompetitive and ultimately put them (and us) out of business, the best case scenario is we loose and end up working to or closer to EASA limits and fly round with eyes out on matchsticks.