This is what the law says about employers restricting employee’s leave
“Some restrictions are not unreasonable, but they should not be operated in a way that discriminates unfairly or that makes it too difficult for workers to take their holiday. The law expects employers to make the rules as clear as possible, to have a clear justification for them, and to operate them consistently and fairly.
The legal right to take holiday is based on the need to protect workers' health, safety and welfare. It is unlawful for employers to make it too difficult for workers to take their holiday. In addition, the law requires employers to actively encourage workers to take their holiday.’
In addition, your employer actually IS breaking the law cancelling your leave at such short notice. Legally an employer CAN cancel annual leave but they have to give the employee as much notice as the amount of leave booked, plus one day. So for example two days notice to cancel one day’s leave and 6 days notice if you have booked a full 5 days, etc. An employer can also insist that you take leave, but there must be work related justification for this, and the same rules apply as to the amount of notice required. If, because of employer imposed restrictions, an employee is unable to take the full entitlement of annual leave stated in the contract, then the employee must be paid for the lost entitlement.
If you have less than two years continuous service, your right to an unfair dismissal hearing is limited. However some things are classed as legally ‘automatic’ unfair dismissal - including ‘constructive dismissal’ and you can apply for a tribunal hearing if this applied. Matters regarding pay and working hours, including the Working Time Regulations, annual leave and the National Minimum Wage are all covered.