Gareth Bale is closer to leaving Real Madrid now than at any time during his seven years at the Spanish club, according to his agent.
Spurs boss Jose Mourinho refused to speculate on the talks on Wednesday.
Bale, 31, left Spurs to join Real for a then-world record £85m in 2013 and has since scored more than 100 goals and won four Champions League titles.
In July 2019, Real Madrid cancelled a deal for Bale to join Chinese Super League club Jiangsu Suning, with the player spending last season at the Bernabeu, playing 20 games.
Barnett said on Wednesday: “We are still negotiating. We shall see how it goes.”
It remains to be seen whether the potential deal will be a loan or a permanent move for Bale.
When asked about the Wales captain, Mourinho replied: “He is a Real Madrid player and I don’t comment on players from other clubs. I have to respect that. It’s better not to speak.
“I tried to sign him for Real Madrid, which was not possible to do during my time there. But the president followed my instinct and my knowledge and the season I left he brought Gareth to the club. It’s not a secret, even Gareth knows that.
“A squad is a puzzle and when a new signing completes the puzzle it’s great for the team.
“There are three more weeks, the market is open both ways. I think in football you have to always be waiting for something to happen. Let’s see what happens to us,” added Mourinho, who was in charge of Real Madrid from 2010-2013.
The Portuguese previously told Tottenham chairman Daniel Levy that he “needs a striker” before 5 October.
Tottenham were beaten 1-0 at home by Everton in their first game of the new Premier League season on Sunday.
‘He carried the Wales team, he carried the Tottenham team’
Former Tottenham winger Darren Anderton says the forward is “exactly what Spurs need”.
“After watching the game on Sunday, oh boy do Spurs need it – someone who can go and win a game with a bit of magic, creativity and flair,” said Anderton.
“It has to be great for all parties. To come back to somewhere you are loved really does make sense.
“He carried the Wales team, he carried the Tottenham team when he was here, winning games on his own. He is exactly what Spurs need.
“For me it is a no-brainer to come and play for us and prove what he is all about.”
Spurs midfielder Eric Dier said it is “exciting” for Tottenham fans “when you are linked with a player of that level”, but does not feel the Spurs squad needs a fresh impetus.
“I would disagree to be honest,” he said. “Since I have been back for pre-season there is new blood.
“[Steven] Bergwijn’s been here six months, and Gedson Fernandes. Pierre-Emile [Hojbjerg] and Matt [Doherty] have just arrived. There’s a different dynamic to the dressing room.