The parents of missing Madeleine McCann want anyone who has spoken to Portuguese police about her disappearance to contact them.

A year on from their daughter's abduction and with their relationship with the Portuguese investigation team having become strained, Gerry and Kate McCann said it was now their right to know what information was out there.

Billing the launch of a new phone line and posters as "May Day for Madeleine", Mr McCann said: "This is something we have been working on behind the scenes, putting into place what we knew was going to be massive media attention on us and trying to capitalise on that to get our message out.

"We have used the (ITV) documentary as a platform, told a story of where we are at to bring the focus completely back to what this was always about, and that's finding Madeleine."

Mrs McCann said: "There has been that much speculation in a lot of the media, particularly the written press. I find it upsetting, but it's upsetting for Madeleine. It's taking away people searching for Madeleine."

With the anniversary of the child's disappearance from a holiday apartment in Praia da Luz falling on Saturday, the McCanns believe this could be a "last chance" in their search.

Because of Portugal's secrecy laws, they have been kept in the dark over much of the information the authorities have collected about her disappearance, despite numerous apparent leaks to the media in Portugal and Spain.

In a London hotel they urged people to call a new phone line - 0845 838 4699 - with any potential leads.

Mr McCann, 39, said: "This is a last chance to capture a lot of information which has maybe gone into the investigation and we are not privy to.

"Clearly we need to know that everything has been done. What we are asking people to do is if you have given information to police, Crimestoppers, the Portuguese police, we are asking you to give it to us as well.

"We are a year down the line and seemingly no closer to finding Madeleine. We have got little bits of the jigsaw but huge gaps and we have a resource, we have set aside considerable resources on this task."

Holding hands, they reiterated that until told categorically otherwise, they still have hope that their daughter, aged three when she vanished, would be found alive.

Mr McCann said: "We will not accept Madeleine's death until there's concrete proof of that. The more searches we have done the stronger my belief that there's a better chance Madeleine is alive than dead."

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