I would speak with your manager/HR once you've done the Magistratetes court as at this point you have been convicted.
As its in your contract that you have to declare, then I would.
On the following basis:
If a reporter is in court, and they decide to public your story then;
- It can be seen as a breach of contract.
- This would then lead to a disciplinary, and they could say "no confidence or trust" / "Breach of contract for criminal offences" both of which are likely to be gross misconduct, and can have a sanction from the employer up to and including dismissal.
I would say, have that open conversation. Explain to your manager what happened, and the steps you have taken to ensure you haven't re-offended for example: If you have an alcohol addiction(not saying you do) that you are attending an Alcohol Treatment Community Programme.
Engage with them, listen to what they have to say about it. Be open. Use open body language.
If they want to refer this to someone more senior or HR then allow this to happen.
More importantly, if you are a member of a union speak with them. If you are no t use this https://findyourunion.tuc.org.uk/
to find if your workplace has one.
They have a duty to keep this information confidential as well.