Under JCT Standard Building Contract 2009, a contract was terminated due to insolvency on behalf of the contractor. Can a liquidator insist that the full payment of the balance plus retention is immediately due?

This is dealt with in clause 8.5 of JCT Standard Building Contract 2009. Under clause, even if no notice in writing has been granted further payment or release of retention no longer apply. The employer’s duty to pay is effectively ended.