Members of the labour union at Hyundai Motor said on Monday they voted in favour of joining a strike proposed by a wider labour group.

According to Reuters, the Korean Confederation of Trade Unions (KCTU), the country's second-largest labour group with 620,000 members, had asked member unions to vote on whether to strike to try and stop changes to the labour law.

The umbrella group also opposes the government's move to sign a free trade agreement (FTA) with Japan, which will most likely help Japanese carmakers gain a larger foothold in the South Korean market, dominated so far by local players, the report added.

"Of total union members, 59.26 percent voted for the strike plan," union spokesman Chang Gyu-ho told Reuters, adding that details of the plan, such as the strike date, still had to be decided.

The news agency noted that Hyundai Motor's 42,000-strong union has been at the forefront of labour disputes this year and is a key force within the KCTU.