By Charles Scanlon BBC, Seoul

President Roh will watch the campaign from the sidelines

Opinion polls have shown a major backlash against the opposition parties that forced through the impeachment vote last month.

The Constitutional Court has up to six months to decide whether to back the national assembly's action.

Mr Roh's powers have been suspended since he was impeached.

Campaigning is getting under way after months of political confrontation that culminated in the impeachment in March of the president.

Strict new rules have been introduced to try to prevent the rampant corruption that has marred previous contests.

The conservative opposition, fearing a liberal landslide, has moved from its headquarters into a tent by the Han river to show repentance for past wrongs.

Stripped of his powers last month, President Roh Moo-hyun can only watch silently from inside the presidential mansion.

A political outsider who promised to reform a corrupt system, he was frustrated by a national assembly dominated by the opposition.

Public fury

But opinion polls indicate a sharp reversal in fortunes.

The small rump of MPs that supports President Roh looks set to win a thumping majority in the election on 15 April.

That is because of public fury at the impeachment over what are widely seen as trivial charges.

President Roh was accused of violating election rules by saying he would like his supporters in the Uri party to do well.

The constitutional court will give a final ruling on the impeachment.

Most analysts expect it to return President Roh to office within weeks.