Communications Minister Stephen Conroy says he plans to introduce legislation for the Federal Government's internet filter in the second half of the year.

Senator Conroy had intended to introduce the legislation in the first half of 2010.

The Government announced the filter two years ago as part of its cyber safety program to protect children from pornography and offensive material. Last year it ran tests on the system.

But the plan has been criticised by internet users who claim it will slow download speeds and lead to unwarranted censorship.

The Opposition claims the Government is delaying the legislation to avoid controversy in the lead-up to the election.

Senator Conroy says he is not sure when the election will be held and argues the delay in the legislation is unrelated.

"We had hoped to bring it in the first half of the year but because of the interest around the consultation paper and the ongoing debate, we wanted to make sure we have consulted thoroughly on the transparency and accountability measure," he said.

Senator Conroy says if the filter was brought in, he would consider allowing child pornography websites to be left online for a short time to catch people maintaining or using them.

He says there is a legitimate debate about whether sites should be blocked as soon as they are discovered or monitored for a time.

"You want to try and go after the people themselves - possibly identify people who are accessing it as well as people who put it up," he said.

"So you may leave it up there a little bit longer so you can try and do that before you actually notify the blacklist."