SCENARIOS-Potential fallout from Britain's expenses scandal

LONDON, May 18 (Reuters) - The leader of Britain's opposition Conservative party called for parliament to be dissolved on Monday, saying it was the only way to resolve a parliamentary expenses scandal that has angered British voters.

David Cameron's call follows demands for the Speaker of parliament, a Labour veteran, to step down, with opposition MPs angry that he was not seen to do enough to prevent the expenses row. If the speaker were to go, it could precipitate further turmoil in the 800-year-old parliament.

The following questions and answers look at the potential implications of the expenses affair

WHAT HAPPENS IF THE SPEAKER OF THE HOUSE STEPS DOWN?

While the speaker, Michael Martin, is unlikely to resign his post and has already sidestepped calls for him to go, if he were to be forced out by internal parliamentary dissent -- via a vote of no confidence say -- it could precipitate a series of events.

Under parliamentary rules, a new speaker would have to be elected by secret ballot. That could prove a bitterly contested, drawn-out affair, with the rules stating that any candidate must get more than half the votes in the house. Labour retains a solid majority in parliament.

WHAT ABOUT DISSOLUTION OF PARLIAMENT, IS THAT LIKELY?