Despite the disarray caused by the sudden mass resignation of election chiefs ahead of next month's polls, candidates for seats in the Iraqi parliament are pressing ahead with unofficial campaigning.

Keeping the printing houses whirring, they have been putting up posters and distributing leaflets.

But wary of breaking the rules, their early propaganda only obliquely refers to the polls, scheduled for April 30, or skirts election regulations by praising the security forces alongside party insignia.

Iraq's Independent High Electoral Commission (IHEC) has taken little action to curb such practises.

Much is at stake as Prime Minister Nuri al-Maliki bids for a third term at a time that violence has surged to its highest level since Iraq emerged from a brutal Sunni-Shiite sectarian war and as the country looks to ramp up oil production.

But the mass resignation of IHEC's board on Tuesday has sparked worries that the polls could have to be delayed, though all major parties insist the vote must be held on time.

Despite the confusion, however, candidates have not taken their foot off the pedal.

"We have printed posters and campaign leaflets for around 15 candidates" so far, said the owner of the Abu Haidar printing house, who only gave his nickname Abu Mohammed, for fear of losing other prospective clients.

Abu Mohammed's shop, which lies near Mutanabi street in the capital's historic centre, was packed to the rafters with campaign posters and election paraphernalia.

Each candidate has spent around $1,000 on campaign materials, and more election hopefuls are coming in, the shopowner said.

He said customers included would-be lawmakers from major blocs including Maliki's State of Law Alliance and the Ahrar list which was until recently linked to powerful Shiite cleric Moqtada al-Sadr.

"Most of them have already started to distribute their electoral publicity material," he said.

Officially, IHEC says campaigning can only take place from April 1 to April 28.

But it has not imposed penalties, instead resorting to calls for posters to be taken down.

Those warnings have done little to stop blocs from pushing the envelope.

The Citizens Bloc -- formerly the Supreme Iraqi Islamic Council, which is seen as close to Iran -- has plastered massive billboards across Baghdad with the catchphrase: "Citizens Want...?"

Individual candidates, meanwhile, have put up their own banners on which tribes praise one of their own as a would-be lawmaker.

In Iraq, election hopefuls typically appeal to voters' ethnic, sectarian and tribal background, rather than campaign on specific policies.

- Blocs walk thin line -

Maliki's State of Law has put up posters of its own, which do not refer directly to the polls but rather show scenes such as a young girl holding an Iraqi flag or an elderly woman kissing a soldier on his helmet.

"It is really just to hold the space on the billboards for our posters," said Samira al-Mussawi, a State of Law MP, referring to the bloc's posters.

"Even billboard places are being divided up for the election."

The efforts highlight the fine line many blocs are attempting to walk, before official campaigning kicks off.

In the end, economics may have more of a greater role than the election commission in restricting the printing of publicity material.

Several printing houses, including the one owned by Abu Mohammed, have been chastened by Iraq's provincial elections held a year ago.

They had printed posters and leaflets for candidates who promised to pay after the polls but later declined because their campaigns were unsuccessful.

"This time," he said, "we are refusing any delayed payments."