Changes to approved share schemes will be announced in the forthcoming Pre-Budget Report, PKF has predicted.
The move is likely because of the Chancellor backing share options for City executives, rather than bonuses, in an attempt to counter the 'untenable bonus culture', said the accountancy company.
Employment taxation and rewards partner Philip Fisher claimed that increasing the value limits for company share option plans would cost no additional tax revenue for three years and would probably be a less controversial move than widening the eligibility criteria for the more flexible enterprise management incentives scheme.
He added: 'A direct attack on the City bonus culture is much more likely than a wider overhaul of tax allowances. The Chancellor has already announced that executives in the newly "nationalised" banks should get share incentives rather than cash bonuses in future, and a new special rate of income tax or NIC on large cash bonuses cannot be ruled out.
'However, if the Chancellor is prepared to give tax allowances a radical overhaul as he did with capital gains tax in the last Pre-Budget Report, then he may restructure these as "tax reducers" to give the lower paid extra benefits.
'Altering the tax and NIC rates for very high earners could also allow the Chancellor to raise additional revenue without having to take the politically damaging step of putting up the basic or higher rates of income tax.'