Binmen staged a second protest on College Green as part of their ongoing strike over pay.

As replacement workers were drafted in from the South East to empty overflowing bins in Bristol, 150 strikers gathered yesterday for a rally and short march.

Waving flags and holding union banners, binmen, refuse collectors and road sweeps reiterated their demands for an improved pay deal from their employer Sita.

They were on strike for the fourth day yesterday and, backed by their union Unite, plan a further one-day strike on Monday ahead of an all-out strike planned from Wednesday.

The industrial action could be avoided if the binmen agree to formal arbitration.

Workers were due to vote on whether to accept an offer of arbitration yesterday but will now be balloted on Monday.

Led by Unite regional organiser Pam Jennings, the workers marched up to the entrance of the Council House yesterday morning and bellowed "Bin Sita. Pay the workers".

They also shouted demands for a meeting with Liberal Democrat leader Nick Clegg, who was inside the building celebrating his party's triumph in the local elections in the city.

Binmen said more than 100 refuse collectors and admin staff had been drafted in from the South East to empty wheelie bins and collect food waste over the weekend and claimed they were being put up in hotels in the city.

Mervyn Thornbury, a Unite union rep based at the Sea Mills depot, said workers were chasing an increase on the 2.75 per cent offer, but were willing to negotiate with bosses at Sita, Bristol City Council's waste contractor.

Of his employer, he said: "We're talking about a company that made a profit of £17 million to the year ending December 2007. All we are asking for is for the company to go above 2.75 per cent and give us a decent pay rise.

"They have brought in workers from Kent, Eastbourne and London to cover for us but there are health and safety concerns and we understand some are working over their hours."

Paul Matthews, a shop steward for Sita, said: "The city council should be imposing fines on Sita for not collecting the waste.

"We don't want to be striking and we don't want to upset the public – we would rather be working. We have families and we have bills to pay but we've been forced into a corner with this."

Sita workers have held four one-day strikes since May 22 in a row over pay and the offer of a 2.75 per cent increase.

They say they should get a pay rise above 2.75 per cent, owed to them from November when inflation was about 4.5 per cent and cost of living was much higher.

But Sita management says 2.75 per cent is a fair offer in the current economic climate.

Up to 35,000 homes are affected by the strikes, with black wheelie bins and brown food waste bins left overflowing and attracting vermin and maggots.

Bristol city councillor Gary Hopkins, executive member for the environment, said he was disappointed the workers had not voted on whether to agree to arbitration.

He said: "This means people in Bristol have had another day of disruption and the workforce goes another day without pay. It doesn't help anybody.

"We can't have a position where waste is not collected in Bristol. We understand the difficulty Sita is having but it's the company's duty to provide a service to Bristol.

"We have the potential to impose a financial penalty on Sita but before doing that we need to take into account how hard they are trying to meet their obligations to us."

The council is advising residents to leave out all bins and waste scheduled for collection.

Sita refused to add anything to comments they had previously made this week.

For more information on refuse collection dates, log on to www.bristol.gov.uk, or call 0117 922 2100.