This is absolutely ghastly. As soon as I heard the news I fell apart and ever since I’ve been staggering about trying to take it all in. The death of people you know is always a shock but with Ant the particularly difficult thing is that he was amazing at enabling and empowering everyone around him. This random thing that seems to have killed him is impossible to imagine – as a writer and director he made things happen, he sorted things, he brought out the best in people’s talents. So to have something as mad as this to end all that doesn’t make sense.

When I think of Ant I think of him walking towards me, my heart opening up. It didn’t matter how long it had been since our last conversation. He had held it all, nothing was forgotten, almost as if some part of me was being carried around by him. He did that for so many people. I remember his smile, being bathed in it for the next few seconds or hours, this joyous exchange. He was complicated, funny, challenging, never banal. Any encounter with him was intensely rich.

Ant was sophisticated, intelligent and creative, both in his life and everything around him. He was a huge person in so many people’s lives, he was loved by so many people; and he fuelled that love with charm, and seemed fuelled by charm in return. That was perhaps part of his Italian/English upbringing: he was a big-hearted, passionate, tactile person. He would be talking to you and rubbing your shoulder at the same time, but without any sense he was invading your space. He was a great celebrator. And yet he had a huge area of privacy reserved for his family life.

I’d known him for years, I was in the first play he directed for radio. I knew him as a writer and how very different an existence that is to directing – he would lock himself away, be very solitary. It’s a lonely process that requires great self-discipline. The obituaries so far have focused on his directing; no one is talking about his writing and in my view he was one of our greatest writers. In Truly, Madly, Deeply he understood that the rhythms of human speech connect to complicated internal loss. The dialogue is extraordinarily rhythmic, coming from the heart, head and the mouth. With beautiful music, it’s the same thing: so many emotions can be elicited in one movement. Ant understood that people write in sentences but rarely speak or think in sentences and so wrote films that are complex maps of how we experience ourselves, relationships and language. It was a great gift.

Truly, Madly, Deeply was an extraordinary work in so many ways. With most directors you start as strangers but Ant and I had worked together before, so we both had short cuts to each other. It was his first film, and first-time film directors find it exhilarating because they can make up their own rules. When someone has as gigantic a talent as he had those rules can be very exciting. He let his imagination fly.

He was good at directing women and had a great fascination for women and actresses. Maybe that was down to his grandmother, who was very up on women and down on men, and to whom he was very close. He wasn’t down on men, but he was not afraid of the femaleness within himself. He was fully a man, but he was very gentle, sensual and had equal friendships with men and women. He adored and was loyal to his wife. When he spoke to you, you really did feel as if you were the only human being in the world. He had the capacity to bring the best out of you, to take you to the edge of yourself and elicit your fullest potential. If he came to see me in a play, that night I would absolutely be playing to him the whole evening, presenting the finest, most sophisticated performance I could.

On a film set, the machinery and hardware are usually central, but on Truly, Madly, Deeply he made the actors and characters the emotional centre of the set. So if you were supposed to be grief-stricken, the whole crew was tuned to that. If you and Alan Rickman were dancing around, the whole crew would be dancing to bebop. He created this atmosphere and made everyone feel extraordinary. He had an intense curiosity for people and was attuned to, and interested in, their foibles, frailties and idiosyncrasies. Whatever your status on the set he brought you in and invested in you. People would do anything for him. He was very unjudgmental.

Ant could be tough but in a gentle and intelligent way. He was intensely self-critical. I had a small part in Breaking and Entering. With most directors you’d be in and out in half a day, but we spent hours and hours on this scene, ad-libbing, extempo-rising, imagining, all for a scene that lasted a few moments. He wrung out every last drop from every scene. He was a perfectionist and very driven and had the highest expectations of people in the best sense. You wanted to meet them. A film set is a huge family and he once told me that directing reminded him of the family café his parents ran, with people swarming around and doors swinging open all the time. He had the capacity for both the writer’s and director’s life. He could be the centre of a huge crowd and also extremely private.

Who knew he would start directing opera [Madam Butterfly for ENO]? He was a giant figure in our cultural life. He would have seen being chairman of the British Film Institute as an opportunity to revive an industry that should be flourishing thanks to the wealth of talent we have. He wanted to stop the drain of people to Hollywood.

This all sounds very serious, but Ant was also into self-mockery. None of the obituaries, or lists of achievements, has mentioned his delicious sense of humour. It infused everything, his work and family. He adored taking the piss out of himself and me. “Why does everyone take you so seriously as an actress?” he’d say to me. “The person I know is a complete lunatic, a nitwit.”

He wrote that into Truly, Madly, Deeply. Everyone thinks it’s a tragic film about grief but he captured all my stupid obsessions and paranoias. It’s a comedy really. Onset, people were very focused but laughing, laughing, laughing. He was so perceptive, he didn’t deal in stereotypes, and so the film is a celebration of the complexity of life and relationships. And he encompassed that too. Ant was many people. He was too big a person to be just one person.

As told to Tim Teeman

Explore Film

• Film Reviews

• DVD

• Oscars

• Bollywood

Editor's choice

• Here comes summer: our cultural must-sees
• Friends reunited: Sex and the City
• New country for old men