Doubt was cast yesterday on the introduction of plain packaging for cigarettes after the Government gave the idea only lukewarm support.

Plain brown or white cigarette packs carrying nothing but a health warning have been widely promoted by the anti-smoking lobby as an important measure to deter young smokers from adopting the habit that kills 80,000 people a year.

Brightly coloured logos are seen as an important way in which tobacco manufacturers market their products to new smokers who may be unfamiliar with the different brands.

But in a report published on No Smoking Day yesterday, the Government offered only muted backing for the idea, committing to "consult on options to reduce the promotional impact of tobacco packaging, including plain packaging, before the end of 2011".

Analysts at Bank of America Merrill Lynch, described the announcement as a "big relief" for the tobacco companies which had expected tougher measures. In a briefing for investors, they noted several caveats in the report, including the Government's acknowledgement that it needed "evidence that plain packaging would have an additional public health benefit," the "likely impact on the illicit tobacco market" [plain packs are easier to counterfeit] and the need to explore "competition, trade and legal implications".

The ban on the display of cigarettes in shops, introduced by the former Labour government, has also been delayed by six months for large shops, to April 2012, and by 18 months for small shops, until April 2015. Government targets to reduce smoking among adults from 21.2 per cent to 18.5 per cent by the end of 2015 were "not aggressive" and implied no reduction in cigarettes sold, after allowing for population growth, they said.

The proposals were welcomed by health organisations, but the Royal College of Physicians criticised the delay to the ban on shop displays. It said "urgent measures" were required if the new target to reduce smoking was to be met.

Professor John Britton, chairman of the college's Tobacco Advisory Group, said: "The Government has accepted that legislation is needed [on shop displays], so we fail to see why its implementation has been pushed back."

The Association of Convenience Stores protested that the measure would cost £40m to implement, and there was no evidence it would work.

Several countries, including Canada, Ireland, Iceland and Finland, have introduced similar shop display bans.

Harpal Kumar, chief executive of Cancer Research UK, said the delay to the display ban was "very disappointing," but plain packaging would be "a giant leap forward". He said: "Research shows that plain packaging reduces false beliefs about how harmful different tobacco products are. We also know that plain packs are less attractive, especially to young people, and they make the health warnings on cigarette packets more effective."

If proposals to put cigarettes in plain, unbranded packs are given the green light by the Government, the UK would become the first country in Europe to make such a move. Australia is due to introduce plain packs in 2012. The British Heart Foundation described the measures as "a victory for public health". Treating smoking-related illnesses costs the NHS more than £50m a week.