Here's what SW says:-
Requalification for JB
If your full Jobseeker's Benefit entitlement has expired, you may requalify for Jobseeker's Benefit when you have paid 13 contributions at the appropriate class after the date of expiry of 156 days of JB. You must also meet all other statutory conditions, including that of a substantial loss of employment prior to making a new claim. If you worked continuously three days a week prior to expiry of their Jobseeker's Benefit claim/entitlement and continue on the same pattern, there would be no substantial loss of employment.