The local welfare assistance scheme for the London Borough of Hackney is called the Discretionary Crisis Support Scheme. For more information see the Hackney Council website, which states that the scheme:

may be able to help with some of the urgent financial needs not covered by regular social security benefits or tax credit payments.

This help takes the form of one-off payments for emergencies or items that are difficult to budget for 

You can download the guide to the Discretionary Crisis Support Scheme

How to apply

Apply through the "partner agencies" that are listed on the website.