The Football League's longest-serving boss, whose side were the last outfit to be beaten by Guy Whittingham's Pompey before his departure last month, met with Portsmouth officials on Tuesday.
And the Grecians confirmed they gave him permission to do so and will not stand in his way should Tisdale be offered the job at their League Two rivals.
A club statement issued on Thursday afternoon said: "We can confirm that Portsmouth Football Club approached Exeter City to ask permission to speak to Paul Tisdale about the vacant management position at Fratton Park.
"As on previous occasions that approaches have been made to speak to Paul, permission was granted. Paul met with Portsmouth on Tuesday for initial discussions.
"Exeter City Football Club prides itself on not standing in the way of staff, players and management when further opportunities arise away from the club.
"Given Paul's excellent track-record at Exeter City, we are always unsurprised to receive approaches from other clubs for his services. We are also delighted with the mutual loyalty between Paul and the club during his seven-and-a-half years at St James Park."
Other names linked with the Fratton Park vacancy include Oxford boss Chris Wilder, former Crawley manager Richie Barker and caretaker manager Andy Awford.