
You may know this already but incase you dont- this is taken from the Act itself
Employer's duties in relation to application under section 80F (flexibleworking)
An employer to whom an application under section 80F is made-
( which I presume you have)
shall only refuse the application because he considers that one or more of the following grounds applies-
(i) the burden of additional costs,
(ii) detrimental effect on ability to meet customer demand,
(iii) inability to re-organise work among existing staff,
(iv) inability to recruit additional staff,
(v) detrimental impact on quality,
(vi) detrimental impact on performance,
(vii) insufficiency of work during the periods the employee proposes to work,
(viii) planned structural changes, and
(ix) such other grounds as the Secretary of State may specify by regulations.
There should also be a meeting between the employer and the employee to discuss an application under section 80F within twenty eight days after the date the application is made;
Hope that helps ?