Pompey will be able to see out the season after receiving loan fees for Stephen Henderson, Hayden Mullins, Erik Huseklepp and Liam Lawrence, but ultimately Birch still needs to find a buyer for the club.
In a statement on Pompey's website, Birch said: "We have stabilised the club to enable it to fulfil its remaining fixtures this season and restructured the operations to make the business as attractive as possible to potential buyers.
"We have also been in discussion with a small number of interested parties, although no offers have been received to date.
"We continue to believe that we can find a buyer for the club before the money runs out and are doing everything we can to achieve this. (This) will result in the best possible outcome for the creditors as a whole, in our view.
"As things stand, we cannot rule out the possibility of having to liquidate the company if our efforts aren't successful. It would be irresponsible to claim otherwise.
“However, we want the club to have a sustainable long-term future and are working hard to make this vision a reality."