Today is 'key' in search for British teenager Jay Slater missing in ...

Today is a "key day" in the search for a British teenager who has been missing in Tenerife since Monday morning, with search and rescue teams hoping "to have good news", a journalist on the island has said.

Jay Slater, from Lancashire, who was holidaying with friends, was last seen on a night out in Tenerife on Sunday evening, having been to the NRG music festival.

Tenerife-based reporter Clio O'Flynn said Thursday "is a key day, the day they [the rescuers] want to have good news and say they've found Jay".

"If he's taken shelter, the hope is he's waiting for help to come along," the journalist told Sky News.

His mother, Debbie Duncan, who flew to the island and has joined mountain rescuers and the local civil guard in the search for the 19-year-old, has called his disappearance "an absolute living nightmare".

She told ITV News: "I wouldn't wish this on anybody. I just want my baby back."

Mr Slater's friend, Lucy Law, told Wednesday's UK Tonight programme on Sky News she spoke to him at around 8.15am local time on Monday.

Mr Slater, an apprentice bricklayer, is "not a stupid boy", she said, but had told her his mobile phone battery was down to 1%.

Ms O'Flynn said: "The problem will be 'does he have a phone signal? Will people be able to locate him? Can he hear their cries?'"

Authorities, she said, are "very, very keen to find this young man, for his sake and the sake of the island".

The search had been "very intense", she added, with teams using all the resources at their disposal, including "mountain specialists, search dogs, drones and helicopters" and are "taking suggestions from his family, so it's very coordinated".

The area where he is believed to have gone missing is a "dry, arid, part of the island", and, given its volcanic origins, has "ravines and gullies", Ms O'Flynn said, warning there are "no lakes, rivers or streams, so it would be quite hard for him to access fresh water".

However, she said the island, the largest and most populous of the Canary Islands, is "not experiencing the sort of heatwaves seen recently in Greece and Cyprus".

Temperatures have been around 26C (79F), she said, but warned that "if you're lost, 25C is very hot".

Ms Law said Mr Slater, from Oswaldtwistle, near Blackburn, told her he had got lost and needed water and had "cut his leg on a cactus".

When she told him to return to where he had walked from, he said he did not know where that was, she said.

He was without food and water, she added, and had been in a T-shirt and shorts. "It's very warm in the day and very cold at night".

Earlier, she told the Manchester Evening News someone Mr Slater had met on his night out had driven him back to their apartment in a hire car without him realising how far away it was.

"He's ended up out in the middle of nowhere. Jay was obviously thinking he would be able to get home from there," she told the newspaper.

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During the short phone call, he told her he had missed a bus trying to get back to his holiday accommodation so was attempting to walk instead - a journey that would take 11 hours.

His phone then cut out, with his last live location showing as the Rural de Teno park - a mountainous area popular with hikers.

A Foreign Office spokesperson said: "We are supporting the family of a British man who has been reported missing in Spain and are in contact with the local authorities."