Here is the advice from the EU. They have heavily based their response wording on the guidance set out in the Practical Handbook for Border Guards referred to below (p28).
"Dear Sir/Madam,
Please find below the reply to your enquiry. Please note that the advice given by Your Europe Advice is an independent advice and cannot be considered to be the opinion of the European Commission, of any other EU institution or its staff nor will this advice be binding upon the European Commission, any other EU or national institution.
Thank you for contacting Your Europe Advice.
We can confirm that you will need a passport that was issued within the last 10 years when travelling into the EU.
The rules on entry into the Schengen area are contained in the Schengen Border Code Regulation 2016/399.
As a non-EU national wishing to travel into the EU from the UK, when crossing the external border of the Schengen area, you will need a passport which was issued within the previous 10 years (Article 6(a)(ii) of Regulation 2016/399 applies).
In addition, when crossing the external border of the Schengen area, a person holding a non-EU passport must usually have at least six months remaining in term of its period of validity (Article 6(1)(a)(i) of the Schengen Border Code applies) in case a person intends on spending 90 days in the Schengen area.
These rules are further explained in the Practical Handbook for Border Guards at page 28:
the requirement that the travel document must have been issued within the
previous ten years must be fulfilled at the day of entry (but not necessarily during the
stay), provided that its validity extends until the end of the stay plus three months;
The Handbook gives the following example to illustrate how the rules work:
A third country traveller arrives on 21 November 2022 for a 20 days stay in the EU
with a passport issued on 23 November 2012 and valid until 23 March 2023. The
entry condition of Article 6(1), point (a), of the Schengen Borders Code is fulfilled,
since at the day of arrival the issuance date was less than 10 years ago and the
validity extends beyond three months after the intended date of departure.
As a result, this means that, on the date of travel, your passport must have been issued in the last 10 years.
You did not tell us your anticipated travel date nor the date of issue of your passport, so we cannot confirm whether your passport would meet the rules.
Unfortunately, there is no exemption from this rule for anyone even British citizens who are beneficiaries of the Withdrawal agreement or those who are family members of EU citizens.
We trust that the above answers your enquiry.
We remain at your disposal should you require further information or advice on EU rights."
