Rejected petition probation period scams

Employers are using probationary periods to hire temporary staff to cover holiday periods or maternity leave.

How the scam works.
Employers advertise a job as full time contract subject to a successful probation period. They hire the employee with no intention of keeping them on beyond the probation period, regardless of thier performance at work.
When the the short term period they needed covering is over the probationary employee is then dismissed for very vague reason (sometimes no reason at all) and they employee is left unemployed with no legal right to sue for unfair dismissal. Manager also use this to sack people on discriminatory grounds.

The government should give probationary employees the right to sue thier employed for unfair dismissal from day one of employment.
Or outlaw the use of probation periods all together.