The Welshman will leave Spain to put the finishing touches on a season-long loan deal from Real Madrid, the PA news agency understands.
Spurs have been in discussions over the last two days to sign 31-year-old Bale, seven years after he left for a then world-record fee, and it appears all financial hurdles have been overcome.
It is reported that Bale will be accompanied on the plane by Madrid team-mate Sergio Reguilon, who will join on a permanent transfer, with the club hoping to announce both deals before the weekend.
Mourinho played a straight bat to questions about Bale’s move on Wednesday and did so again after watching his side survive a scare in the Europa League second qualifying round against Lokomotiv Plovdiv.
The Portuguese said: “I cannot comment, I don’t comment on something that I don’t know.
“For me, at this moment, until I’m told Gareth Bale is a Tottenham player, I still think and feel and respect the fact that he’s a Real Madrid player, so I’m not going to comment on a Real Madrid player.”
The Spanish club are understood to be paying a large chunk of Bale’s sizeable salary.
Left-back Reguilon, who was interesting Manchester United, is primed to make a £27.5million move on a five-year deal after Spurs swiftly concluded negotiations for his services.
There is thought to be a buy-back clause inserted in the deal by Real Madrid.
Bale’s return will tug on the heart strings of Spurs fans after a hugely successful first stint at White Hart Lane.
The Cardiff-born player swapped the north London club for the Spanish capital in 2013, winning four Champions Leagues during a medal-laden spell at the Bernabeu.
But Bale has found himself marginalised under Zinedine Zidane and spent the last two years struggling to get in the side.
His return to Spurs is also timely for Mourinho after a dismal start to the campaign against Everton on Sunday, when they looked void of all creativity in a sluggish 1-0 loss.
They also needed two goals in the final 10 minutes to overcome Bulgarian outfit Plovdiv, having gone a goal down with 19 minutes remaining.
