Ross County midfielder Brittain signed a pre-contract with Saints but now wants to back out of the agreement, sparking a war of words between Lomas and rival boss Derek Adams.
Lomas admits it is now time for the men at the top to resolve the issue, insisting that he will have to strengthen his squad regardless of whether Brittain does make the move or not.
"It's now a contractual thing and the chairman will deal with it," Lomas said in the Daily Record.
"My rebuilding plans don't hinge on him coming or not but ideally you'd want it sorted out. It's not something that's good for any party but it's down to the chairman to sort it out with Roy.
"I've had my say and I don't want to say any more. There's no timescale on it but the clubs will have to sort it out.
"We've got five players for next season so we're going to have to recruit regardless of what happens with Richie.
"It's not just about Richie. We've got a lot of work to do."