Agony for McCanns as they reveal details of their first holiday since Madeleine vanished

The two-week break was haunted by painful memories of missing Madeleine, who vanished during the family's last holiday together, Mr McCann said.

The couple, both 40, knew the holiday would be difficult for them but decided it was important for their other children, three-year-old twins Sean and Amelie.

Lacking: The absence of Madeleine was further pronounced when the couple holidayed with their twins Sean and Amelie

Writing on his internet blog, hospital consultant Mr McCann said: 'We have recently managed to have a break visiting family.

'Sean and Amelie have had a brilliant time and it has been great for me to spend so much time with them.

'Although this has been a relaxing break, it has been incredibly difficult for Kate and me to have been on holiday without Madeleine - it is all too apparent what is missing.'

The family returned from Portugal last September, four months after Madeleine vanished in the Algarve, and since then they have rarely spent more than a weekend away from their home in Rothley, Leicestershire.

Missing: Madeleine McCann disappeared 434 days ago

But they are determined to give Sean and Amelie as normal a childhood as possible, despite their ongoing search for Madeleine, and decided a family holiday was a vital part of that.

Mr and Mrs McCann are waiting to learn when the 14-month police investigation into the disappearance will be closed, and whether they will be formally cleared as official suspects in the inquiry.

Reports in the Portuguese press have warned they could still face charges of neglect over their admissions that they left Madeleine, then three, alone with her younger brother and sister while they went out for dinner nearby with friends.

Police have handed their final report to prosecutors, but further investigations could still be ordered if they feel there is any slim chance of a breakthrough in the case.

In a sign of the continuing political pressure surrounding the case, the Portuguese Attorney General said yesterday that prosecutors must make a decision by the end of the month.

Fernando Pinto Monteiro said he felt the time had come to set a 'reasonable deadline' for a decision.

The case is widely expected to be shelved and the Attorney General did not appear to hold out any hope that it would be solved.

He said disappearances were 'extremely difficult to solve' and added: 'There are crimes that are solved and others that are not.'

A statement from his Lisbon office estimated that, internationally, about 80 per cent of all missing children cases worldwide remain unsolved.

If the Madeleine case is shelved the strict secrecy laws surrounding the investigation will be lifted and the couple's lawyers will be allowed to see the 11,000 documents contained in the case files.

Mr McCann said their legal team had not been told when a decision might be made, but said they had been warned that the secrecy of justice laws would be in place until August.

And he appealed to other holiday-makers to 'remain vigilant' and to look for Madeleine around the world.

He said: 'We have not heard anything officially other than we know the files are with the prosecutor and the period of secrecy has been extended to August 14.

'Our independent investigation continues and we urge people going on holiday to remain vigilant.'

Madeleine vanished from her family's rented holiday apartment in Praia da Luz on May 3 last year, and there have been scores of reported sightings of her from across the world.

But despite global appeals to find her and a team of private detectives employed by the McCanns' Find Madeleine appeal fund, there have been no confirmed sightings of the youngster since her disappearance.