But the weakness of Brown's position is that if you add his 258 Labour lawmakers to Clegg's 57 then it only gives them a total of 315, still short of the 326 required for a bare majority in the Commons, which initiates and passes legislation. It would be a perilously unstable coalition, looking for others allies among nationalists from Wales or Scotland or among Ulster Unionists. Add Clegg's 57 to Cameron's 306 and you have a healthy 363.