Keeley Hawes and Ed Stoppard's stairway to heaven

He looks most at ease in a velvet smoking jacket, and her hands are not for scrubbing stairs: Keeley Hawes and Ed Stoppard are simply born to rule. They play Lord and Lady Holland in

Upstairs Downstairs will be a feel-good drama, not fuel for class war, according to Ed Stoppard, who plays diplomat and head of the household Sir Hallam Holland. He has a silly name but a kind nature. 'Upstairs characters have just as much heart as Downstairs characters,' says Ed. Standing next to him in real life, Keeley is a little taller and obviously has eyes for no one but her husband, but on screen they make a handsome pair. And not for the first time: ten years ago she played his psychotic girlfriend for a BBC short, Murder in Mind. 'I murdered someone he was having an affair with while sleepwalking,' she remembers. 'With my slippers on, using a club hammer.' Upstairs Downstairs was much more enjoyable. She loved her character's bias-cut satin dresses –'the 1930s are a very kind period, costume-wise' –while he looks dapper in a bespoke suit. 'The costume designer tracked it down at Angels. It's the same one I wore for Brideshead Revisited,' he says, referring to the 2008 film in which he played the eldest Flyte, Bridey. 'I love that suit. I'd like to be stylish in everyday life but my twin girls are just at the age when they would splatter me in soup.'

Ed, son of Sir Tom Stoppard and the agony aunt Dr Miriam Stoppard, found it easy to step into the role of paterfamilias. He is married to Amie, an American photo-grapher, and has three small daughters, Esme, six, and identical twins Maggie and Evie, four. 'We've only dressed them the same a handful of times. Amie and I want to let their individualities grow and now they've gone their separate ways.'

Perhaps their confidence stems from his: he's full of intellectual braggadocio, coming out with corkers such as 'There's a reason some of Shakespeare's plays aren't performed much –they're crap!' and postulating that arts spending cuts might invigorate the industry: 'There's definitely room for production companies to be a bit more careful with their budgets If Alan Sugar or Philip Green got hold of a film or TV
company they'd probably be appalled.'

Mercurial and chatty, Ed rolls up his white grandad-shirt sleeves and tells me public school and he 'didn't gel'. He went to Stowe but didn't make any lasting friendships. He read French at Edinburgh before training at LAMDA and endured a period of anxiety about his famous surname when he con-sidered changing it to Straussler – his Czech-born father's original name. Now, at 36, he seems to be coming into his own.

He laughs a lot, clowning about with Matthew Macfadyen – with whom he starred in the recent TV drama Any Human Heart – but he tells me he is most at ease alone. 'I'm quite pensive and insular. I can spend hours, days, weeks on my own and be perfectly happy. Maybe it's why I'm cast in quite a lot of damaged, conflicted roles... I've never played a cheerful chappie.' His roles have included Hamlet for the English Touring Theatre, and Tchaikovsky in a BBC drama-documentary. He was also Adrien Brody's hungry-eyed younger brother in Roman Polanski's war epic The Pianist. He has a compact action-figure body and eyes that crinkle with thoughtfulness: he can definitely do intense.

What are his abiding memories of Stoppard family Christmases? 'We were very lucky – we sometimes had skiing Christmases or visited friends in Scotland.' (His parents broke up in 1992, when he was 18, and his stepfamily extended temporarily to include his father's lover, the actress Felicity Kendal, and, on his mother's side, the former GlaxoSmithKline chairman Sir Christopher Hogg, who Miriam married in 1997.) 'One year, when I must have been five or six, my brother and I woke up very early, of course, and saw that on the floor were paper arrows, one with an 'E' on for Edmund and one with a 'W' for Will. One led one way and one the other. I followed mine but I only had to go about ten paces and there was a rocking horse. I remember thinking: "A rocking horse? Really? I'm sure I asked Santa for an Action Man..." Then I found my brother and he had a Grifter – the bike everyone wanted. I remember being just speechless and woke my parents up and started complaining about being given a girl's present. That's a powerful memory.'

For his 21st birthday his father gave him a year's membership of The London Library, which he still finds 'a wellspring of infor-mation. I read up on the Indian civil service to help with my character in Upstairs Downstairs, who has just come back from India.' He also researched Kenneth Stoppard, his father's stepfather, an officer who brought his father up in India. This Christmas will be a strictly nuclear affair, in Spain. 'I've been working non-stop for the past eight months and I just wanted the five of us to have a week together.' Ed will pull his weight with the cooking ('I'm famous for my River Café courgette pasta') but they will miss the first broadcast of Upstairs Downstairs on Boxing Day. 'Sitting down watching myself on TV is not my idea of a good time,' he says.

Ed is the youngest of four, and so is Keeley. 'Lots of actors are the youngest of big families,' says Keeley. 'My youngest, Ralph, is already a real showman. He sits at the head of the table and regales us all. It's youngest-child syndrome.'

Keeley grew up in Marylebone, the daughter of a cabbie and a housewife. She lost her London vowels at elocution classes at the nearby Sylvia Young Theatre School. 'My mother brought us up and my father worked all day. It was a very normal childhood. We never went on holiday and we were never spoilt – except at Christmas. Then we were indulged.'