Spurs reportedly opened proceedings with a typically lowball offer of just over 2 million euros (£1.7 millions) but the La Liga side are thought to be holding out for around 5 million euros (£4.2 million).
The report suggests negotiations are amicable and ongoing, with Spurs expected to return with a second offer in the coming days.
Tottenham's Michel Vorm
Spurs have one of the world’s best goalkeepers between the sticks, in Hugo Lloris, but Michel Vorm has failed to provide adequate competition and a younger, hungry back-up would bring welcome depth.
At 21-years old, Pau Lopez is experienced beyond his years and became Espanyol’s first-choice stopper just one year after being promoted from the youth setup.