Portside

STOCKHOLM, Nov 17 (Reuters) - Dockworkers in Sweden pledged on Friday to refuse to offload Tesla (TSLA.O) cars at any of the country's ports as they expanded their industrial action in sympathy with Tesla workers' demands for collective bargaining agreements.

Tesla, co-founded by billionaire Elon Musk, does not manufacture in Sweden, but its electric cars are serviced by more than 120 mechanics affiliated with Swedish union IF Metall, which began a strike on Oct. 27.

Dockworkers joined the strike by mechanics on Nov. 7, blocking Sweden's four largest ports to Tesla cars. That was expanded to all ports on Friday at 12 a.m. (1100 GMT)

A spokesperson from the union Transport, which counts the dockworkers as its members, said that Swedish ports often saw one to three shipments of Tesla cars a week, but no shipments had arrived since the start of the strike.

"So the blockade is working," the spokesperson said.

U.S.-based Tesla, which has revolutionised the electric car market, has managed to avoid collective bargaining agreements, which cover wages and conditions, with its roughly 127,000 workers and Musk has been vocal about his opposition to unions.

Marie Nilsson, head of IF Metall, told Reuters on Friday that the union had received some indications early on in the dispute that Tesla was engaging in strike-breaking tactics by flying in workers from other countries.

"We have never experienced anything like this before... we haven't dealt with this in Sweden since 1937 or so," Nilsson says.

"And this has forced us to escalate the conflict," she added.

If Sweden can break Tesla's resistance, that could provide a precedent for other countries.

So far, unions in the United States and Germany have failed to force the carmaker to accept collective bargaining agreements.

"If they have come to Sweden, they must follow the rules. We have certain norms here and he (Musk) must accept them," Torbjorn Johansson, negotiation secretary at Sweden's LO labour confederation, said.

"Swedish workers cannot afford to lose this fight."

Swedish unions have achieved success before getting foreign firms to accept local industrial practices.

In the 1990s, American toy company Toys "R" Us signed a collective bargaining agreement with its 130 Swedish employees after a three-month strike.

Nilsson said IF Metall had no plans to stop the strike action anytime soon.

"As long as it is needed," she said.

In addition to dockworkers, unionised cleaners are refusing to clean Tesla buildings and postal workers have stopped delivering mail.

On Friday, electricians stopped service and repair work for Tesla, including at its charging stations across Sweden.

Swedish workers are also supported by Norway's Fellesforbundet, the biggest union in the country's LO confederation.

Action against Tesla in Sweden is due to escalate further - if no agreement is reached - on Nov. 24 when about 50 unionised workers at Hydro Extrusions, a subsidiary of Norwegian aluminium and energy company Hydro (NHY.OL), will stop work on Tesla car products.

Tesla has not responded to repeated requests for comment.

Reporting by Marie Mannes Additional reporting by Louise Rasmussen, Johan Ahlander, Ilze Filks and Johannes Birkebaek Editing by Simon Johnson, Mark Potter and Susan Fenton