Espanyol are holding out for a better deal.
Spurs are said to have offered the Catalan club €500,000 (£431,000) up front, with a view to a permanent deal through a €7 million (£6.04 million) bid.
However, Los Perquitos have rebuffed this initial offer, but the goalkeeper is still expected to travel to London to finalise a move.
Pau Lopez in action for Espanyol against rivals Barcelona
Spurs have intensified their interest in the Spanish Under-21 international following an injury sustained to number one goalkeeper Hugo Lloris last weekend.
Pau Lopez is expected to travel to North London to finalies a move to Spurs
It was reported by fichajes.net earlier in the week that Mauricio Pochettino would be willing to meet Pau's £13 million buy-out clause, whilst the Mirror have claimed that the Spurs hierarchy are hoping to have the deal wrapped up in time for their clash against Palace on Saturday.
Should Pau be eligible to make the squad, he would have to be registered by 12pm on Friday.
Back-up stopper Michel Vorm, as things stand, remains the most likely candidate to fill in between the sticks in the absence of Lloris.
Pau was Espanyol's first choice stopper last season, despite being the tender age of 21.