Transcript of today's speech by Sir John Sawer - Chief of MI6 - to the Society of Editors, London

The Times published a reader's letter earlier this year. It read: "Sir – is it not bizarre that MI5 and MI6, otherwise known as the secret services, currently stand accused of being – er – secretive?"

I may be biased. But I think that reader was on to something rather important and most government work these days is done by conventional and transparent processes. But not all.

Britain's foreign intelligence effort was first organised in 1909, when the Secret Intelligence Service was formed.

We have just published an official history of our first 40 years. I'm sure you will all have read all 800 pages of it.

The first chief, Mansfield Cumming, used to pay the salaries of SIS officials out of his private income, dispensed in cash from a desk drawer. I'm glad to say that, even after the chancellor's statement last week, I'm not in the same position.

SIS's existence was admitted only in 1994. We British move slowly on such things.

And this, I believe, is the first public speech given by a serving chief of the British Secret Intelligence Service.

"Why now?" might you ask. Well, intelligence features prominently in the National Security Strategy and the Strategic Defence and Security Review, published last week.

We often appear in the news. Our popular name – MI6 – is an irresistible draw. We have a website, and we've got versions in Arabic and Russian. We recruit our staff openly, with adverts in the national press.

But debate on SIS's role is not well informed, in part because we have been so determined to protect our secrets.

In today's open society, no government institution is given the benefit of the doubt all the time. There are new expectations of public – and legal – accountability that have developed. In short, in 2010 the context for the UK's secret intelligence work is very different from 1994.I am not going to use today to tantalise you with hints of sensitive operations or intelligence successes.

Instead, I want to answer two important questions: what value do we get from a secret overseas intelligence effort in the modern era? How can the public have confidence that work done in secret is lawful, ethical, and in their interests?

Gareth Williams was an enigma, in life and death. Investigations by the police and the security services have left us in the dark as to why the MI6 spy died. The coroner's
verdict was that he was probably unlawfully killed did nothing to abate conspiracy theories.