No. You can pay your deposit with a credit or debit card without registering with PayPal (although registering could prove easier in the long run).
Just click "Pay with a debit or credit card" and enter your credit card details, when prompted on the screen (as shown below):
Please enter all the required details, tick the box to confirm that you consent to Paypal's Privacy Policy and click the 'Pay Now' button.
PLEASE NOTE: if you have or have had a Paypal account in the past (or the card you are using is linked to a Paypal account) you may be asked to pay using this Paypal account rather than a credit/debit card. If you have any queries about this, please direct them to Paypal in the first instance so that they can help.