Council tax payers are being invited to figure out how much they could save or lose by the introduction of a local income tax.

Glasgow City Council is taking the lead with a ready reckoner on its website that can be used by residents of any part of the country, letting each household compare current bills with liability to an extra 3p per pound on income tax.

The idea is intended to inform the council's response to the Scottish Government proposals for local income tax.

But coming from one of the two Scottish councils with majority Labour control, the initiative is an effective means of highlighting those who could lose out under the SNP's local taxation plans.

Nationalist ministers want to abolish council tax in 2011, and to replace around £2bn of council funding each year with a combination of local income tax and increased central government grants.

The plan is to keep the level of additional income tax to a flat rate of 3p in the pound, meaning a 15% increase in tax bills for those on basic rate. That could require two-fifths of the council tax revenue take to be replaced by a central government grant. Glasgow City Council has commissioned independent consultants, with expertise in public finances, to look at the potential impact, and it was reckoned the authority could face a funding gap of £130m per year, unless the rate is set around 5p.

However, Labour reckons the most significant weakness of the scheme is a backlash from people who could lose out. That includes those in lower value houses but with multiple incomes.