Turkey's parliament passed a law on Tuesday to round up millions of stray dogs and put them into shelters despite protests by animal lovers and criticism from the main opposition party, which vowed to challenge the legislation in court.

The law, drawn up by President Tayyip Erdogan's ruling AK Party, has touched a raw nerve in Turkey, where many think it will lead to large numbers of dogs being put down.

Turkey has an estimated 4 million stray dogs and supporters of the law cited concerns about attacks, road accidents and rabies. Under the new rules, any dogs showing aggressive behaviour or that have untreatable diseases will be put down.

It was approved with 275 votes in favour and 224 against.

Animal rights activists have called instead for neutering campaigns to be stepped up, and the opposition Republican People's Party (CHP) said it would appeal against the legislation in the Constitutional Court.

"The bill is clearly unconstitutional and does not defend the right to life," CHP leader Ozgur Ozel said after it passed, adding that municipalities had limited resources to deal with the task of taking so many dogs off the streets.

"We will do more than what is required of us in terms of building more shelters, vaccination, neutering and adoption, but it is not possible to completely fulfil this burden with the power that municipalities have," he added.

The country currently has 322 animal shelters with a capacity for 105,000 dogs, according to the bill, far short of what would be needed to round up the number of strays.

The law requires all municipalities to spend at least 0.3% of their annual budget on animal rehabilitation services and building or upgrading shelters, though they will be given until 2028 to do so.

Thousands of people have taken to the streets over the past few weeks to protest against the law, occasionally scuffling with police and carrying banners including slogans such as "You cannot kill them" and "Take back the law".

Residents of Turkish towns and cities often take care of street animals, putting out makeshift shelters, food and water for them. One survey showed less than 3% of people supported putting them down, while nearly 80% were in favour of dogs being put in shelters.