During his time with the publication, MacAskill has been chief political correspondent, diplomatic editor, Washington bureau chief, New York-based reporter, and defence and intelligence correspondent, as well as part of the Guardian team who won a Pulitzer Prize for our coverage of the Edward Snowden story.

When did you decide to become a journalist?

The catalyst was a school trip to the Scottish Daily Express, based in Glasgow. The deputy chief sub-editor showing us around was obviously well-liked and there was a lot of banter between him and other journalists and with the printers. That was it for me. I never wanted to be anything else. That deputy chief sub eventually ended up at the Guardian, Ian Jack. And so, happily, did I.

How did you come to the Guardian?

I was on the Glasgow Herald and the Scotsman and had a couple of stints working overseas. I was interviewed by then editor Alan Rusbridger in 1996. The interview went badly - neither of us is particularly loquacious and there were a lot of awkward silences - but he gave me the job anyway.

Do you remember your first day on the Guardian and how it felt to be here?

I was taken on as chief political correspondent. I had been in Northern Ireland for a few days for the Scotsman covering an outbreak of trouble. I flew back to London for a lunch at the Guardian office for the then Labour leader Tony Blair. I immediately liked the general lack of deference shown towards Blair. That set the tone for the next 22 years. We cannot be flattered, bullied or pressured.

In the run-up to the war in Iraq in 2003, I was writing the splash. Blair and Bush had met in the Azores for a final mini-summit ahead of the invasion. I can’t remember the intro now but it was something like UK and US on verge of war. Alastair Campbell phoned and asked what I was doing. So I told him. He said that is not the story: it should be Blair secures Bush pledge on Israeli-Palestinian conflict. I told him I was not writing that. Ten minutes later, the deputy editor Paul Johnson came to see me and said Campbell had phoned the editor to complain I had the wrong intro and it should be Israel-Palestine. Paul asked where the reference to Israel-Palestine was. I said paragraph four. He said: “Make it paragraph 18.” That is the attitude I liked.

Did the Guardian live up to expectations?

Yes. Kath Viner joined a few months after me and rose to become editor-in-chief. I stayed as a reporter but I think I got the better deal. Reporters have more fun.

You started out at Westminster – what was that like?

The Guardian office in parliament was a happy one. Then political editor Mike White and sketch-writer Simon Hoggart bickered like brothers but were funny with it. Around six o’clock, one of us would bring in a tray of drinks and we would sit drinking beer or wine as we wrote. I doubt if the political team still does that but who knows?

I was involved in the story that saw the first resignation from the Labour government, Peter Mandelson, forced out of the cabinet over a hidden mortgage deal. I had gone with colleague David Hencke, who found the story, to meet the source in a greasy-spoon cafe near Westminster. We have never disclosed the source. The identity is as interesting as the story itself.

What stories had the biggest impact on you?

After Westminster, I was on the foreign team for 14 years, travelling all over the world. I covered various conflicts but the one that had the most impact was Israel-Palestine. I have not been back in over a decade but it is still vivid. I interviewed Yasser Arafat, the leaders of Hamas and Islamic Jihad, Israeli soldiers, settlers and the victims of violence.

One of the reasons the Guardian gained popularity in the US was its opposition to the Iraq war. How did you come to write about that?

Deputy editor Paul Johnson, who has, by a long way, the best news sense of anyone I have worked with, was sceptical about the case for war with Iraq from early on and threw lots of reporters at it, including me. I went to Iraq several times before and after the invasion.

Tell us about covering Obama’s two White House elections.

I arrived in the US early in 2007 and one of the first things I did was to go to Iowa to see Hillary Clinton speak. She was favourite to secure the Democratic nomination for the White House race but I was disappointed: she was all platitudes and cliches. When I saw Obama speak for the first time, I thought he could win, even though he was 30 points behind her.

What have you done since you came back to the UK?

I have had a varied beat. I did defence. And spies. I was part of the team which covered the Scottish independence referendum. It was great to see so many people engaged in and passionate about politics. I found the same engagement and passion when covering Corbyn’s leadership campaign.

Your biggest story was meeting National Security Agency whistleblower Edward Snowden in Hong Kong in 2013. What was the most memorable moment?

The first time I met him. Holed up in a hotel room, his behaviour seemed odd at first. He had cushions lining the door to prevent eavesdropping. He placed a soya sauce bottle on top of absorbent paper and left it behind the door when he went out: if there was a spill, he would know someone had been in. He pulled a red hood over himself and his computer to protect his password. But he was the real deal, a genuine whistleblower. With the US intelligence hunting for him, he had good reason for being paranoid.

What else stands out from that time?

Then US editor Janine Gibson showed courage in publishing the first of the stories. On a conference call, they tried to flatter her with an invitation to the White House. They tried to intimidate her. She told them she was going ahead with publication.

What was it like to be played in a Hollywood film, Snowden?

It was nice to be portrayed by Tom Wilkinson. But it never felt like me. He refers to Ed as ”‘laddie”. I have never called anyone “laddie” in my life.

Are there any stories you wish you’d written?

Simon Goodley’s undercover reporting exposing working conditions at Sports Direct. That is what the Guardian is all about.

What have been your biggest mistakes?

The stories I knew about but did not write. Confessing to them all would make foreign and home desks cringe. But here is one: one of Gaddafi’s sons hinted to me a few days in advance Libya was going to get rid of all its weapons of mass destruction. It sounded implausible. I could not find a source to back it up so did not write it. When the Libyan government made the announcement – it was December 2003 - it was big news all around the world, a genuine surprise to most people. Unfortunately not to me.

Why did Donald Trump call you a “nasty, nasty guy”?

It was at a press conference in Scotland in 2016. I challenged him over his claim of popularity in the UK. I told him he was toxic in Britain. I was banned from his next press conference.

What advice would you have for young journalists starting out?

They do not need advice from me. I recently taught young journalists from around the world. One of them had covered the fall of Aleppo. Another had revealed a huge medical scandal in Africa.

What has been the Guardian’s greatest moments during your time here?

Alan looks benign but he took on every part of the establishment and presided over a great run of stories: WikiLeaks, phone-hacking and Snowden. Since Kath took over, the stories have kept on coming: Milly Gentleman on immigration; Carole Cadwalladr on Cambridge Analytica; Juliette Garside and her team on the Panama and Paradise Papers; and Martin Chulov on Islamic State.

What have you been proudest of?

One of the best things about the Guardian is the morning conference. Unlike other news organisations, it is open to all staff, everyone free to speak. It is part post-mortem, part a look forward. Sometimes passionate. Occasionally heated. At its best, it throws up good story ideas. Over the last few weeks, knowing I was leaving, I have looked around at the faces, thinking ‘I am so glad I was part of this. I am glad I was one of you’. There has never been a day I was not proud to be part of the Guardian.