THE Coalition has bowed to pressure and will support the plain packaging of cigarettes.

The decision, which means every MP and senator except Bob Katter now supports the measure, puts beyond doubt the passage of the legislation, a world first, and sets the scene for a legal battle between Big Tobacco and the federal government.

The Coalition's decision came after a robust discussion in the party room yesterday in which 16 MPs spoke for and against.

Originally Mr Abbott said the Coalition would not adopt a policy position until it saw the final legislation, which the government was planning to release next month.

But public support was strong and the Coalition was finding itself in an increasingly indefensible position. The government also accused the Coalition of being beholden to Big Tobacco, as the Liberals and Nationals still accepted donations from cigarettes companies.

The legislation was set to pass anyway because the government had the numbers in both houses.

On Monday the shadow cabinet decided the Coalition should cut its losses.

The Nationals opposed the plain green packets with graphic health warnings, saying it infringed the intellectual property rights of tobacco companies. Several Liberals held the same view. As a face-saving measure, the Coalition will seek to amend the legislation by having the new larger graphic health warnings but retaining some branding.

Mr Abbott said if this amendment failed - which it will - the Coalition would wave the original legislation through.

Inside the party room, some MPs such as the NSW Liberal Alex Hawke argued against plain packaging, saying it was another step towards the ''nanny state''.

At the other end of the spectrum, the WA Liberal MP and medical doctor, Mal Washer, said it was a health matter and warned the party ''we are just going to bleed on this all the way to July''.

Others, such as South Australian senators Simon Birmingham and Cory Bernardi, argued the middle ground. They said by at least trying to amend the legislation to protect branding rights, the Coalition would be vindicated should the government lose the court case.

Because the plain packets would be a world first, the government believes other nations will follow should Australia succeed.

The Coalition decision removes an irritant for Mr Abbott, which has contributed to recent tensions in his ranks.

He pointedly told yesterday's meeting that the party was at its best when focusing on the government and its ''failures''.

''When we talk about ourselves, we do less well,'' he said.

Yesterday the Health Minister, Nicola Roxon, was presented by the World Health Organisation with an award for her ''unwavering leadership'' in promoting plain packaging. The WHO's regional director, Shin Young-soo, said her action ''will impact on tobacco control policies in many, many other countries''.

The Foreign Minister, Kevin Rudd, said he had rejected appeals from members of the US Congress to drop the plain-package plan.

''We will defend our position on these matters robustly,'' he said.

Ms Roxon welcomed Mr Abbott's decision and urged him to go further and reject tobacco company donations.

Tip of the day: Kent source.