London Welsh have confirmed that forwards Nathan Trevett, Koree Britton, Nathan Morris and Ben Cooper have all signed new deals with the club.
The Exiles currently sit at the bottom of the Aviva Premiership table with just one point from their 19 games so far.
"Today's announcement is hugely significant as we prepare to mount a challenge for an immediate return to the Premiership," director of rugby Steve Lewis is quoted as saying by Sky Sports News.
"There is a substantial amount of experience in these re-signings and also in the group already in contract, and this will be essential next season."
London Welsh continue their league campaign on March 25 when they face Leicester Tigers at Welford Road.
