Mr Henderson's was captured on 12 September

The ELN group said army operations in the Sierra Nevada mountains meant Mark Henderson and four Israeli hostages would not now be released.

The 32-year-old from Lincoln was one of eight trekkers captured near the Ciudad Perdad (Lost City) ruins.

Another Briton, Matthew Scott, escaped soon after the abduction.

Mr Henderson's mother, Sharelle said: "We were hopeful he would be home for Christmas, the church leaders were hopeful he would be and we were relying on that.

It's all hope anyway until he is on that plane and hopefully it could all change again Mark Henderson's mother, Sharelle

"We are bitterly disappointed to hear this news that there may be a problem.

"As the church had intimated that all of the hostages would be freed before Christmas this news is extremely disappointing.

"The church has worked non-stop to make sure something happens and, while we are disappointed at this stage, hopefully the situation will change again and he will be home for Christmas.

"It's all hope anyway until he is on that plane and hopefully it could all change again."

A Spaniard and German were released two weeks ago and observers hoped the rest of the hostages would be released before Christmas.

In a communique addressed to the Israeli and British governments, the National Liberation Army, or ELN, said: "The lives of your citizens have been put at risk in an irresponsible way by the army."

The group said it could no longer guarantee the necessary security conditions to release the backpackers, as planned, before Christmas.

But the Foreign Office said there had been no direct contact with its representatives in Colombia.