STANDARDISED tobacco packaging has been cleared to finally go ahead later this month after Europe's highest court rejected a series of legal challenges.

The European Court of Justice (ECJ) ruled that the Tobacco Products Directive, which was adopted in 2014 but has been held up by a series of court cases, is lawful, meaning picture health warnings must cover 65% of the front and back of every packet of cigarettes, with additional warnings on the top of the pack.

It includes a ban on menthol cigarettes and "lipstick-style" packs aimed at women - all packs must have at least 20 cigarettes to leave room for health warnings - and a ban on promotional statements such as "this product is free of additives" or "is less harmful than other brands".

The directive also allows the UK to go further and introduce its own regulations requiring all tobacco packaging to be uniformly olive green with large images designed to act as health warnings.

However, the UK regulations are currently subject to a High Court judicial review brought by all four major tobacco multinationals, and a judgment is expected imminently.

The new regulations will not go ahead if the ruling is in favour of the tobacco companies, but campaigners consider this to be unlikely, especially after the ECJ's decision.

In its ruling today, the ECJ said extensive standardisation of packaging, the future EU-wide prohibition on menthol cigarettes and the special rules for electronic cigarettes are lawful.

The court rejected a legal challenge brought by Philip Morris International and British American Tobacco, with Japan Tobacco International and Imperial Brands acting as interested parties.

The court said: "The court finds that, in providing that each unit packet and the outside packaging must carry health warnings ... the EU legislature did not go beyond the limits of what is appropriate and necessary."

The new rules are an attempt to cut the number of smokers across the EU by 2.4 million.

An estimated 700,000 premature deaths are caused each year, and cancer charities are backing the measures.

Deborah Arnott, chief executive of health charity Ash, said: "The European Court of Justice decision is no surprise: the directive is lawful and the UK is allowed to go further than the directive in standardising tobacco packs with respect to matters not harmonised by the directive.

"We await the UK court judgment, which is expected shortly, but we are optimistic that the court will confirm that the introduction of standardised packaging in the UK is lawful.

"From May 20 all packs manufactured for sale in the UK will have to be plain, standardised, in the same drab green colour with the product name on the pack in a standard font."

But Simon Clark, director of the smokers' group Forest, said the directive "treats adult consumers like children".

He said: "Smokers know the health risks and they have a right to buy and consume tobacco without excessive regulations that are designed to stigmatise both the product and the user and reduce consumer choice."

Vassilis Vovos, western Europe regional president of tobacco company JTI, said: "This outcome does not end the main arguments in the legal case under way in the UK - that plain packaging illegally destroys our brands."

A Department of Health spokesman said: "Smoking is the biggest cause of premature mortality and kills over 100,000 people every year in the UK.

"We warmly welcome the judgment that the Tobacco Products Directive is valid and will press ahead with the important public health measures set out in it which are aimed at discouraging children from smoking and helping smokers to quit.

"The new requirements for tobacco products, e-cigarettes and herbal products will come into force on May 20 and are expected to result in £13 billion in health benefits in the UK alone."