The Senate has passed the Federal Government's plain packaging laws for cigarettes, with amendments to the start date.

The new packaging laws are now due to come into effect in December next year, six months later than the original time frame.

Due to the amendments, the legislation will first have to return to the Lower House for approval.

The legislation bans the use of company logos and requires all cigarette packets to be a dark green colour.

Pictures of diseased body parts, sickly babies and dying people will cover 75 per cent of each packet, and tobacco industry logos, brand imagery, colours and promotional text will be banned.

Since it was announced in 2010, the plan has faced fierce opposition from tobacco companies who have vowed to mount a court challenge against the legislation.

Tobacco industry spokesman Scott Macintyre has predicted the Government will have to spend "millions of dollars" fighting challenges in court, followed by "potentially billions of dollars" in compensation to the tobacco industry.

"We've invested billions of dollars into these brands. Unfortunately, it looks like the Government is pushing us down that path," Mr Macintyre told the ABC.

But Health Minister Nicola Roxon says she does not buy the argument the Government will have to pay billions in compensation.

"They're using that as a way of threatening both the Government and the Senate to try not to proceed with this law," she said.

"We're ready for that if they take legal action. We hope that they don't."

Australia will become the first country to introduce plain packaging laws and Ms Roxon says the move will reduce the number of deaths from smoking-related diseases.

"It will give our country the best chance of having the lowest smoking rates and, of course, that will mean many lives are saved and many families that don't go through the grief and pain of seeing someone die because of a tobacco-related illness," Ms Roxon said.

The Australian Institute of Health and Welfare estimates 15,500 Australians are killed by tobacco-related diseases every year and says passive smoking affects the health of children.