Scotland goes to the polls on 3 May next year

The Holyrood and local authority votes will take place on the same day, but under different voting systems.

MPs will discuss the Arbuthnott report on how to improve Scotland's voting system in the Commons on Thursday.

The Tories will ask Scottish Secretary Douglas Alexander to persuade the Scottish Executive to hold the polls on different days to avoid confusion.

People in Scotland go to the polls on 3 May next year.

The council elections will be conducted under the single transferable vote (STV) system for the first time.

Separate elections for local government and the Scottish Parliament would also allow for real local accountability David Mundell Shadow Scottish Secretary

The Scottish Parliament uses the additional member system (AMS), a form of proportional representation where people cast one vote for a candidate and one for a party.

Ministers have already announced that the votes will be counted electronically to speed up the process.

However, the Arbuthnott Commission had recommended that the elections be held on different days.

The Conservatives claim that First Minister Jack McConnell has ignored that advice.

Shadow Scottish Secretary David Mundell said the Commons debate could be the last chance to avoid "electoral chaos" next year.

Polling station

He said using two different voting systems on the same day was "a recipe for disaster".

"It is hard enough to get people to vote so it is absolutely unacceptable to make the process so confusing that they cannot exercise that vote when they get to the polling station," he said.