£900,000 more to find says Rochdale ONLINE

The local website ROCHDALE ONLINE estimates that the new councillor's

allowances voted through by Labour and the Conservatives will cost near

an additional £900,000:

The massive increase in councillors' allowances - voted for by councillors at last week's full council meeting - means the total cost of the allowances paid to councillors will rise to just under £900,000, an additional £172,600 per year.
The basic allowance (BA) for each of the 60 councillors will be £10,451 (a 34% increase).

• http://www.rochdaleonline.co.uk/news-features/2/news-headlines/106924/shouts-of-disgraceful-as-councillors-vote-themselves-a-massive-34pc-increase 

However, the basic allowance increase has a cascading effect on many other 'extra' allowances, known as a special responsibility allowances (SRA) - these are paid on top of the basic allowance.
Half of all councillors receive a special responsibility allowance.
The SRA of council leader Richard Farnell is calculated as three times the basic allowance. The others are calculated as a percentage of the leader's SRA.
The massive rise in the basic allowance gave the leader an additional rise in SRA, which in turn gave the other councillors in receipt of a special responsiblility allowance an additional rise*.
For example, the Leader of the Opposition Conservative Party, Ashley Dearnley, will now receive a basic allowance of £10,451 plus an SRA of £10,974, a total of £21,425 (previously BA of £7,812 + SRA of £9,372 = £17,184).