You may withdraw as a candidate by signing and submitting a withdrawal notice, which must be witnessed by one other person.1
There are no restrictions on who may submit the notice, but it must be delivered by hand. Your witness must also sign the notice. You can obtain a notice of withdrawal from the Greater London Returning Officer.
If you are outside the UK and want to withdraw, your election agent can sign the withdrawal notice on your behalf. The withdrawal must be accompanied by a written declaration stating that you are absent from the UK.2
The withdrawal notice must be submitted by the deadline for withdrawals (i.e. by 4pm on 24 working days before the poll).
After the withdrawal deadline it is not possible to withdraw from the election, and your name will appear on the ballot paper.
If you withdraw as a candidate, your deposit will be returned.3