If you are in receipt of certain means tested benefits you may be able to get a loan to help you meet an emergency or essential expense.
Hardship Payments
If you are struggling to meet your basic needs because your universal credit or other benefits have been sanctioned, you may be able to apply for a hardship payment. This is a loan, which you will need to pay back.
Step Change have useful information on hardship payments.
Budgeting Loan
If you have been on certain benefits for 6 months or more, you may be eligible for a budgeting loan to help pay for things like traveling in the UK, furniture, white goods, funeral expenses, moving costs, rent in advance, clothing, footwear, and repaying loans taken for these items. You will need to pay this money back from your benefits. You can find a full list of acceptable expenses and see whether you may be eligible on the Government website.