Blue Planet Foundation, a clean-energy advocacy group, joined Hawaii’s Consumer Advocate in asking the state to dismiss Hawaiian Electric Co.’s request to import liquefied natural gas for power generation.

In a Tuesday filing, Blue Planet said the Public Utilities Commission should dismiss HECO’s $458 million plan to convert its power-generating units on Oahu, Maui and Hawaii island to LNG because it depends on the commission’s approval of NextEra Energy Inc.’s $4.3 billion purchase of the utilities’ parent company as well as HECO’s recently filed 30-year renewable-energy plan.

Lawyers for the Division of Consumer Advocacy said in a filing made public Thursday that the PUC should suspend or dismiss HECO’s application to use LNG because it depends on decisions that have yet to be made by the agency.

Richard Wallsgrove, policy director at Blue Planet Foundation, said that dismissal is more appropriate than simply suspending the applications.

“Procedurally, Hawaiian Electric’s request to import huge volumes of LNG suffers a number of problems,” Wallsgrove said. “At this stage it’s unclear whether Hawaiian Electric could justify spending any money to import a new fossil fuel like LNG — let alone spending more than $1.3 billion on retrofitting old power plants, building a new fossil fuel plant, buying LNG tanks, and all the other equipment that would be necessary.”

Hawaiian Electric Co.’s LNG plan also depends on the approval of the construction of a new power plant, which would cost $859 million.

When HECO submitted the application in May, the utility said it expects LNG will save customers between $850 million and $3.7 billion over 20 years — the amount depends on future oil prices.