SITTING side by side, with quiet dignity, Kate and Gerry McCann spoke for the first time yesterday of the guilt they felt for leaving Madeleine unattended at the time of her disappearance - and addressed the criticism being levelled at them.

In their first in-depth interview, the couple spoke about the "darkness" they felt in the hours and days after their daughter's abduction and admitted they had been "naive" to leave their three children unsupervised during dinner on the evening of 3 May.

"The guilt that we feel having not been there, irrespective of whether we had been in the next bedroom or not, will never leave us," Mr McCann said.

He also spoke about the criticism they had received.

"No-one hurts you as much as the hurt that we had, but we have tried to remain very positive in our outlook and even small levels of criticism make that hard when you're trying to do everything in your power to get your daughter back."

Questions over whether her parents were mistaken to leave Madeleine and her siblings alone have remained virtually taboo in media coverage of the case.

But yesterday, the couple chose to tackle the issue themselves head on.

Asked why they did not use the babysitting facility provided by their resort in the Portuguese town of Praia da Luz, Mr McCann said: "All the families were checking on the children at very regular intervals and often in very close proximity. It is what we had done during the week.

"As we had arranged to dine so close, we felt that it would have really disturbed the kids dropping them off at a crèche at a time they were sound asleep and then bringing them back.

"That was the reason why we didn't use that.

"For us it was like dining in your garden. Admittedly at the bottom of your garden, but you could see the flat and we were checking so regularly.

"Not for one minute would anyone have thought that someone would abduct your child. We were really going back to make sure they weren't crying."

Mrs McCann said: "I think we were naïve. We are very responsible parents. We love our children very much. I don't think any parent could imagine or consider anything like this happening.

"Certainly the first few days you torture yourself with that, but we've had so many letters of support and calls from people saying, 'we would have done exactly the same'. Certainly in those early days that's very important to hear.

"Looking at it from where we are now I don't feel we were irresponsible. [But] you can't help but have emotions like that."

Last night it emerged that a friend of Madeleine's parents may have seen her being taken from the holiday apartment on the night she vanished.

A source indicated that the sighting - the most striking so far in the case - was by one of the couple's party who has not been named.

The Portuguese Policia Judiciaria issued a description of a white man aged 35-40

who was seen "carrying a child or an object that could have been taken as a child" in Praia Da Luz at 9.30pm.

Policia Judiciaria finally released the man's description in the face of possible legal action by Madeleine's parents.

The information, likely to have been released early on as a matter of course in other countries, had to be sanctioned by the public prosecutor.

It was released after an "amicable" meeting between senior Portuguese police and the McCanns, believed to have been on Thursday.

The McCanns are convinced the figure seen being carried was Madeleine.

The description released last night is similar to that included in reports that a man was seen dragging a girl in a road towards the marina at nearby Lagos.

The marina was the focus of searches in the days after Madeleine's disappearance.

Chief Inspector Olegario Sousa said dozens of reports of Madeleine's possible whereabouts were still being checked.

The wall behind the couple at yesterday's interview was covered with missing person posters of Madeleine in her pink hat and red dress, clutching a toy and smiling

Mrs McCann particular struggled to remain composed during the interview, as she clutched one of her missing daughter's favourite toys.

Mr McCann said the experience of his daughter's abduction was "worse than your worst nightmare", but said they had drawn strength from thousands of messages of support from around the world.

The couple described how they have been dealing with Madeleine's abduction in the presence of their two-year-old twins Sean and Amelie.

Mr McCann said: "We have said she's gone on a little trip just now and Amelie came out with one really cutting line that went right to the core. She said, 'Madeleine's on trip, back soon'.

"We certainly pray for that every day."

Mr McCann smiled as he described Madeleine's personality, saying that she was a "ringleader" and had enjoyed her holiday a game in which she would shout: "Be a monster, be a monster".

Asked in the interview whether things could have been done differently in the vital first few hours after Madeleine disappeared, Mr McCann said:

"It's fair to say we expected a very British response that you would expect if you were in a big metropolitan city. But we are in a tiny resort. The time for these lessons to be learnt will be after the investigation and not now."

Asked whether the couple still felt negative thoughts, Mrs McCann said: "I think in the early days we did and I think that's inevitable. Any parent who has been through this... We don't now, we're a lot more hopeful.

"We have to be hopeful, it's what keeps us going, keeps us focused."

A TERRIBLE ACT THAT HAS ROBBED US ALL OF PEACE OF MIND
EVERY parent has taken a risk: I've nodded off on the sofa, only to wake in a sweat because my subconscious has reminded me that the toddler is holding a biscuit and could be choking on it.

When you are focused on protecting the most precious thing in your life, taking your eye off the ball, even for a moment, can feel like a terrible dereliction of duty.

When Kate and Gerry McCann spoke of their feelings of guilt at having left Madeleine and her siblings alone while they ate dinner 100 yards away, only the paragon of parenthood could have reacted without sympathy, or the slightest shiver of recognition.

I've been on holiday and sat in a restaurant with just a wall between me and my baby. I had the baby monitor with me and felt secure that, if he cried, I could be there in seconds. It never occurred to me that I should repeatedly return to the locked bedroom to make sure he was still there.

Since the disappearance of Madeleine, I keep asking myself, what should I do in the future? Everybody with small children is probably wondering the same thing.

Do we pop them in the car seat in the hope that they'll snooze, then take them out to dinner with us? Or do we eat with them at 6pm and spend the rest of the evening sitting with them in a darkened room?

The McCanns felt - not unreasonably - that as they were staying in a holiday village that catered for families, they could relax as everybody there was like them. We now know that wasn't true, but that wasn't their failing.

Whoever took Madeleine has done more than destroy her parents' lives; they have robbed us all of our peace of mind.