Transparency, Yes. Interference, No.

There was a time when public health discussions on tobacco were an extraordinarily open process. Government officials met a wide range of people and listened to their concerns and ideas as they formulated policy.

Among the "contributors" were representatives of the tobacco industry, which offered assurances about its earnest intentions. The tobacco industry had access to policy-makers and infiltrated public health forums and because everyone involved was open the industry gained access to internal government documents listing a wide range of ways of regulating the industry.

All that changed when courts, particularly in North America, began considering cases from tobacco victims. Judges ordered - as is normal in such matters - that the tobacco industry discloses internal documents to plaintiffs. It became clear that the industry lied when denying the harms caused by their products, disputing scientific findings, and luring millions, including the world's youth, into addiction, in a drive to build its business.

The publication of this mountain of paperwork (the documents are now numbered in the millions) from the late 20th and early 21st centuries was a watershed moment, providing incontrovertible evidence that the tobacco industry could not be trusted. There was no sign of the earnest partner the industry claimed to be.

Documents show how the industry worked behind the scenes successfully lobbying policy makers to discontinue or water down tobacco control measures. The documents mapped efforts to delay and confound policy initiatives and to create vast new markets in the developing world. They also show how the tobacco industry created or co-opted front groups to defend their interests and used tobacco farmers to prevent governments pushing on with public health policies.

As British American Tobacco's (BAT) chairman noted in an internal memo in 1990: "We should not be depressed simply because the total free world market appears to be declining... There are areas of strong growth, particularly in Asia and Africa... it is an exciting prospect."

The revelations kept on coming, including the disclosure that industry research was suppressed or secretly moved to other countries to put material beyond the reach of the courts. Other documents showed how the industry conspired in attempts to raise the proportion of women smokers to the levels of men.

The tobacco industry documents had a significant effect - firstly on the court cases to which they related, but just as importantly in creating a resolution among policy-makers. If the tobacco industry was now a global industry seeking to expand to new markets, the response must be equally global.

The UN Tobacco Control treaty itself, the WHO Framework Convention on Tobacco Control (WHO FCTC), was a response to the transnational nature of the business and the need for a global response to curb the epidemic. It entered into force in 2005 becoming the first global health treaty, an attempt to strongly regulate the trade in this noxious product.

The Convention brought together various government sectors with public health experts, researchers and others in the certainty that unified action was required to counteract the industry's behaviour. This, we fervently hoped would save millions of lives.

We have been successful in doing so, even as we recognise that the tobacco industry is expanding its markets, placing many more people at risk of premature death.

The tobacco industry is targeting Parties' delegations attending the world's largest intergovernmental meeting solely dedicated to tobacco control. At the last Conference of the Parties in 2014, letters were sent representing tobacco industry interests petitioning finance officials on taxation.

We cannot sit at the negotiating table with the people who caused this global disaster because one thing is crystal clear - this industry lies. Publicly it speaks in a mild voice, while behind the scenes it executes policies in absolute opposition to its public statements, ultimately killing one in every two regular users of its products.

So when we meet in Delhi in November for the WHO FCTC's seventh session of the Conference of the Parties (COP), we will be making documents available, we will be briefing journalists and we will publicize our decisions.

We will also guard against tobacco industry interference, this most untrustworthy of businesses. It would be a dereliction of our duty to do otherwise.

That means some sessions will be held in public and some behind closed doors, normal in international meetings and as provided by the rules of the FCTC Conference of the Parties. We will be as open as possible, but we are not naive. We have learned a critical lesson - this industry can never be trusted and will try to disrupt and confound the tobacco control process.

COP7 will, I believe, send an unequivocal message to the tobacco peddlers. The world understands who you are and what you do, and is determined to stamp out the global plague which you do so much to spread.