A Hawaii state senator tried to influence a Honolulu Police Commission member to vote against a pricey severance package for a retiring chief under federal investigation, according to a letter from the commission chairman.

Sen. Will Espero sent an email the night before the vote to Commissioner Luella Costales that said, “If you are thinking of running for office again, your vote tomorrow will be significant.”

Commission Chairman Max Sword complained about Espero’s email in a letter to Senate President Ronald Kouchi.

The tone of the message was “at worst threatening, at best disrespectful and discourteous,” Sword wrote. Kouchi couldn’t immediately be reached for comment Wednesday.

Espero has been a critic of the commission and opposed paying former Chief Louis Kealoha $250,000 for agreeing to retire amid the probe into corruption allegations.

Espero said the commission overreacted and he wasn’t trying to influence Costales.

“I was sharing my thoughts on the matter,” he said. “Ultimately it was up to her.”

Espero said Costales has been his friend for more than 15 years and he was simply reminding her that voters would remember where she stood on the severance issue.

Costales said the email didn’t affect her decision to approve the retirement package. She declined further comment.

In the email exchange with Espero, she took offense at the idea that she could be motivated by political ambitions.

“For the record, I have no intention of seeking office again,” she wrote. Espero replied with an apology.

Costales’ term on the commission ended in December, but she remains on the panel until the mayor appoints a replacement. She ran unsuccessfully in 2012 for a state House of Representatives seat representing Mililani.