MOO
That's not how MOO "works".
If you're an employee working in project 'X', you can be told to go and work on project 'Y'.
If you're a contractor working on project 'X', then you cannot be required to switch to working on project 'Y' (assuming you have a decent contract in place).
Contracts can also be terminated, usually be either party - there may be penalties for doing so, and it is common for termination clauses to be heavily biased in favour of the client.