If the contractor you engage does not have the financial wherewithal to carry out your project, then you change contractor, not provide him with a bank guarantee.

If he defaults, you would have no project and would still have to repay the bank.

Had this condition been known at the time of tender there could have been many more submissions.

Responsible contractors build in the cost of a bank guarantee into their tender price.

This government guarantee vitiates the whole process.

I suspect that if other tenderers set up a court challenge, they would have a strong case.