Not unless the main contract expressly says so. If the employer pays the sub-contractor, he will still be liable to the insolvent main contractor. It is an interference with insolvency law to pay the insolvent company’s creditors directly. The creditors should claim in the insolvency. Many people consider this to be unfair and one of the proposed reforms to the Housing Grants Construction and Regeneration Act is a proposal to allow payment direct to the sub-contractor. However, the prospects of this succeeding seem very slender.