UK is still in the EU for a couple of years.
The UK remains a member of the EU, the earliest leave date would be March 2019 (any transitional arrangements might extend that date).
Travel and entry requirements are not changed if your trip is March 2018.
>>> But since England is not in EU anymore I have doubts. <<<
The United Kingdom does not leave the EU until 30th March 2019 at the earliest. Although to be fair, you only sound as misinformed about Brexit as the average Brit.
Whether EU citizens will require full passports when/if the United Kingdom leaves the EU is one of the many details that have yet to be negotiated.Edited: 30 January 2018, 13:28
<<. But since England is not in EU anymore I have doubts.>>
Since when did we leave the EU? The trigger has been pressed but nothing has changed in the UKs status yet and will not for some time - certainly not by March. Everyone is still working out what it actually means, so I very much doubt anything will happen before the two years in the relevant treaty article is up.
The UK is still in the EU, but not in the Schengen area, so you will have to show your passport on entry. The fact that you are an EU citizen means that you will not need a visa.Edited: 02 February 2018, 21:09
If you are a citizen of an EU or EEA member state that issues national identity cards, you can use the ID card instead of a passport, and you do not need a visa.
What happens after Brexit no-one knows yet, but my guess is that the arrangements will be broadly similar to those currently in force.
Unless you are planning to swin across the sea, you will need some sort of ID for the plane or train, so don't even think of coming without it.
If the UK decides not to accept European ID cards as travel documents after a full Brexit, you can expect the EU to take retaliatory action, requiring UK nationals to apply for Schengen visas for example or even cancelling all UK-issued passports which still bear a "European Union" imprint. Those ID cards have been accepted long before the UK joined Europe and many EU citizens don't have passports because they don't need them.
Post #8 - scaremongering. Won't happen
If they will not accept a UK passport with "European Union" on the front after Brexit, they will be cutting their nose off to spite their face, because it will have a severe adverse effect on UK tourists visiting the EU, which is worth a lot of money to the EU and supports many EU jobs. Similarly if they require all UK visitors to have Schengen visas.
Conversely, as tourists from the EU are important to the UK economy, it is unlikely that the UK government would want to do anything which would adversely impact this.
As no-one knows what will happen after Brexit, suggestions that ID cards will not be accepted or that visas will be required are simply scaremongering.Edited: 30 January 2018, 18:06