Four tests for Osborne's Budget

With the Coalition taking pre-Budget briefing to new levels you’d be excused for thinking there’s little we don’t know about tomorrow’s statement. But here are four questions we can’t yet answer, and that will be crucial to assessing whether this is a Budget for low-to-middle earners as the Chancellor claims: 

1) Will the new increase in the personal allowance be restricted to basic rate taxpayers? When the Coalition raised the allowance by £1,000 back in April 2011 they cancelled out the benefits to those at the top by lowering the 40p tax threshold. The second time around — the £630 increase that kicks in this April — they didn’t. From the sound of things, Osborne is now set to announce a further large increase in the allowance for 2013 and possibly even beyond. So will he focus the benefits on basic rate taxpayers this time?