If they do dismiss you, it already looks like a potential unfair dismissal as you have asserted a statutory right and to dismiss on this basis constitutes a potentially unfair dismissal.
Have a read of this case summary I found on the net - not entirely on point, but it takes you in the right direction when talking to a employer lawyer:
'In the recent case of Elizabeth Claire Care Management
Ltd v Francis, the Employment Appeal Tribunal (EAT)
held that an employee was automatically unfairly
dismissed after complaining that she had not been paid
her wages on time.
The Employment Appeal Tribunal found that her employers had made an
unlawful deduction from the employee’s wages pursuant
to s13 (1) of the Employment Rights Act 1996 by paying
her 4 days late. The employee had made several
telephone calls to her employers seeking an explanation
for the late payment and the EAT found that in doing so,
she had asserted a statutory right i.e. the right not to
suffer unlawful deductions. The EAT held that despite
the employer’s arguments to the contrary, the real
reason for the employee’s dismissal was her assertion
of a statutory right, resulting in an automatically unfair
dismissal.'
