Section 19(3) of the Organisation of Working Time Act 1997 provides that an employee is entitled to two unbroken weeks of annual leave each year (if they have worked for 8 months in that leave year).
An interesting aside:
Under the organisation of Working Time Act the employer must grant/offer two unbroken weeks of annual leave each year (the employee can accept take individual days throughout the year. So in your case if you have already taken 10 days statutory leave in bits and pieces your employer cannot insist you take days here and there to cover periods when you are sick. He must offer you two unbroken weeks of leave.