Any MP convicted of fraud should face a minimum punishment of 6 Months in prison

No MP should receive a lesser punishment than an ordinary person.
Draft a law stating that any MP convicted for expenses fraud cannot receive a punishment at a lower level than any ordinary citizen for benefit fraud.

We're not sure exactly what you'd like the Government or Parliament to do. MPs are subject to the same criminal laws as other citizens. Decisions about sentences in individual cases are the responsibility of the courts, which are independent.

You could start a new petition explaining clearly what you would like the Government or Parliament to do.