Some strikers at an Alberta slaughterhouse appear poised to go to jail on Monday rather than comply with an injunction that limits their picket activities, after RCMP charged two plant managers in a weekend collision that injured a union leader.

A spokesman for the United Food and Commercial Workers' Local 401 said that tempers were high among pickets outside Lakeside Packers in Brooks on Sunday, the fifth day of a bitter strike.

"The mood is distrust of the government and the police," said union representative Archie Duckworth.

Three cars collided Friday on a road near the entrance to Lakeside Packer in Brooks, Alta.

Lakeside's parent company, the Arkansas-based Tyson Foods, shut down production at the plant over the weekend, but said it plans to ship 1,000 workers across the picket line on Monday.

The union has officially told striking members to comply with the court order, but Duckworth said he didn't know how many people would listen.

"I believe there are lots of people willing to go to jail," he said. "But that's not an answer either."

Edil Hassan, one of the pickets, summed up the mood of many on the line on Sunday.

"We are going to do every action that can stop them," she said. When asked whether that included going to jail, she replied: "Doesn't matter. What matters is we keep our dignity."

Pickets can't stop vehicles, court rules

The Court of Queen's Bench granted an injunction on Saturday that prohibits the union from stopping employees from crossing the picket line.

The court also ordered the union to have no more than 50 pickets on the line at a time and said they must be 200 metres from the plant gate.

The ruling stemmed from violence that broke out after the strike began on Wednesday, when two buses were damaged and several pickets were injured as the company tried to send buses through the picket line.

The incident resulted in police laying three charges against O'Halloran: two counts of willful damage and one count of possession of a weapon for a dangerous purpose over the incident.

It wasn't the only outbreak of violence: fights broke out as buses carried managers and workers from the plant on Thursday.

4 people charged in highway crash

But pickets are most upset by a three-vehicle collision near the plant on Friday night that sent the local's president, Doug O'Halloran, to hospital.

On Saturday night, the RCMP said dangerous driving charges had been laid against two senior managers at the plant and two plant workers.

The company has declined to comment. But the union has said it wasn't an accident and accused the men of deliberately running its leader off the road.

The RCMP rejected union calls for more serious charges to be laid. "Based on reasonable and probable grounds, dangerous driving was the most reasonable offence that applied to the four individuals charged," RCMP Cpl. Wayne Oakes said on Sunday.

The union called the strike after nearly a year of failed negotiations as union members try to get their first collective agreement. It said it has support from about 1,500 workers of the more than 2,400 people who work at Lakeside, the largest employer in the city of about 12,500 people.

The company has said that 1,000 employees are willing to cross the picket line and go to work. Some Lakeside employees tried to get the union decertified earlier in the week, but failed.

The trouble has been further fuelled by a racially charged atmosphere at the plant, where about 60 per cent of employees are immigrants, many from Sudan.

Many locally born workers are among those who want to go back to work, while many of the new Canadians have been picketing.

Workers were prepared to walk off the job in July, but the day before they were set to hit the picket line, the province stepped in and imposed a disputes inquiry board to talk to both sides, halting any job action for 60 days.

The report from the one-man panel, which wasn't binding, was accepted by the workers, but rejected by Lakeside Packers last month.

In July, labour relations experts had predicted that a strike at the plant would be lengthy, similar to the last job action at the facility in the 1980s, which killed the union local representing workers there at the time.