London Irish are "getting close" to confirming their return to the capital.
Chief executive Brian Facer says the club, who are bottom of the Premiership, are looking at "serious alternatives" to Reading's Madejski Stadium, their home since 2000.
A ground-share at Brentford FC's new Lionel Road stadium in west London appears to be the preferred option.
"Whatever we do, it will be done with proper grounding and proper backing," Facer told BBC Sport.
Brentford want the 17,250-seat Lionel Road stadium ready by December 2019 after revised plans forced them to postpone the start of construction.
Irish have already been granted a licence by Hounslow Borough Council to play at the new stadium, but the club's current commitment to Reading runs until the 2025-26 season.
"We've been talking about it for a long time," Facer said. "But, we won't make any decisions without having them backed up by feasibility studies and making sure we're doing the best for the club.
"It's about bringing the club back to the heart of where it was, back to our history and heritage. We want to be a true London club, the clue's in the name after all.
"But it's about looking at serious alternatives. We're not writing anything off at the moment."
Other potential options within the M25 could include a ground-share at AFC Wimbledon's new Plough Lane stadium, also set to open in the 2019-20 season.
'Club is not for sale'
While Irish are on the verge of Premiership relegation for a second time in three years, takeover speculation has surrounded the Sunbury-based club during Facer's first few months as CEO.
The former Northampton commercial director succeeded Bob Casey in October and stressed the club is seeking "additional investment" rather than a change in ownership.
"The club is not for sale, we're trying to find a stable platform," he said.
"We're very lucky and blessed to have an owner who's committed to us and has been for a period of time. His commitment is still there.
"We'd like to find some extra commitment to prop up and support what Mick Crossan is doing.
"It's about finding a number of committed, stable investors who want to put money in to help us become a top six club in the future.
"We're in the early stages of an investment process where we've reached out to people who might be interested.
"There are people there we can look at working with us. But, it's a long process and we don't want to put the club into problems by going in with the wrong investors or people."