SYDNEY (Reuters) - Google and Facebook-owner Meta Platforms ( META ) urged the Australian government on Tuesday to delay a bill that will ban most forms of social media for children under 16, saying more time was needed to assess its potential impact.

Prime Minister Anthony Albanese's centre-left government wants to pass the bill, which represents some of the toughest controls on children's social media use imposed by any country, into law by the end of the parliamentary year on Thursday.

The bill was introduced in parliament last week and opened for submissions of opinions for only one day.

Google and Meta said in their submissions that the government should wait for the results of an age-verification trial before going ahead.

The age-verification system may include biometrics or government identification to enforce a social media age cut-off.

"In the absence of such results, neither industry nor Australians will understand the nature or scale of age assurance required by the bill, nor the impact of such measures on Australians," Meta said.

"In its present form, the bill is inconsistent and ineffective."

The law would force social media platforms, and not parents or children, to take reasonable steps to ensure age-verification protections are in place. Companies could be fined up to A$49.5 million ($32 million) for systemic breaches.

The opposition Liberal party is expected to support the bill though some independent lawmakers have accused the government of rushing through the entire process in around a week.

A Senate committee responsible for communications legislation is scheduled to deliver a report on Tuesday.

Bytedance's TikTok said the bill lacked clarity and that it had "significant concerns" with the government's plan to pass the bill without detailed consultation with experts, social media platforms, mental health organisations and young people.

"Where novel policy is put forward, it's important that legislation is drafted in a thorough and considered way, to ensure it is able to achieve its stated intention. This has not been the case with respect to this Bill," TikTok said.

Elon Musk's X raised concerns that the bill will negatively impact the human rights of children and young people, including their rights to freedom of expression and access to information.

The U.S. billionaire, who views himself as a champion of free speech, last week attacked the Australian government saying the bill seemed like a backdoor way to control access to the internet.

($1 = 1.5454 Australian dollars)