A Friday deadline loomed for workers and bosses to reach a settlement, but unions said there would be none since the company had not called off the plant closures.
"We are going to keep up the fight. We are not going to come to any agreement while they are planning closures and layoffs," said Ramon Gorriz, one of the leaders of the CCOO labour union.
Workers have been on strike all month over plans to close four bottling factories, including one in Fuenlabrada in southern Madrid. They say the plan is unjustified since the plants are profitable.
"Coca-Cola is not 'the Real Thing' for Spanish society. It has shown that it is an exploitative multinational which is only after profits," Gorriz told a news conference.
CCOO and Spain's other main trade union UGT said the Spanish subsidiary Coca-Cola Iberian Partners had offered improved payoffs and relocation deals but still planned to close the plants.
They said the company's offer lowered the number of jobs threatened to 1,190 from 1,253 previously, but that the plan would still mean forced layoffs.
Coca-Cola Iberian Partners did not immediately respond to calls for comment on Thursday.
CCOO blamed the dispute on the Spanish government's 2012 labour reform, which made it easier to hire and fire workers. The government said that was necessary to strengthen the economy.
A double recession over the past five years has pushed Spain's unemployment rate up to 26 percent.
CCOO leaders threatened legal action if the company pushes on with the plan, as they expect it to do when Friday's deadline passes.
On Madrid's central Puerta del Sol square, a small crowd of Coca-Cola workers in red t-shirts protested on Thursday, blowing horns and yelling for the layoffs to be scrapped.
"We feel cheated by the company. They're offering us more money to sign the deal and leave," said Johnny Garcia, who has worked for 24 years mixing the secret Coco-Cola formula in Fuenlabrada.
"At 45 years (of age) and with the job market in Spain the way it is, it will be difficult for me to find another job."
The strike has also won plenty of popular support with some consumers banning the popular beverage.