What happens if a guarantee from the Contractor’s parent company is still not provided after the four week fall-back period?

NEC3 and NEC4 Contracts Secondary X, W and Y options
1

What happens if a guarantee from the Contractor’s parent company is still not provided after the four week fall-back period?

2

Failure to provide a guarantee within the four week fall-back period entitles the Project Manager to notify of a default under Clause 91.2.