People need look at what the EU may look like in the future as it progressively moves towards its stated aim of ever closer union.
At present all 28 EU member countries have their own separate seats on world organisations, - such as 28 sets on the United Nations, own seats on World Health Organisation, own seats on G20 etc.
At present all 28 EU member countries have embassies throughout the world and their ownAmbassadors.
The EU is already trying to replace the representation of its separate member states with just one EU seat on these global and international organisation.
Since the Lisbon Treaty, the EU has had what's called 'legal entity'. that means the Lisbon Treaty made the EU an actual 'thing' that can make deals in its own right and can make treaties and can be sued. The EU therefore exists in its own right. Since then it has started having its own EU ambassadors too.
The EU now has observer status at the United Nations. Once it has its own UN seat there will be no need for all its constituent states to have their seperate UN seats - the EU will do that for us.
From Wiki
The EU holds an observer seat on the executive board for funds and programmes, where the European Commission is a big donor and Mark Malloch Brown, former UN deputy secretary general, believes the EU will gradually be represented more and more, starting with the aid departments, eventually leading to the EU taking up a seat on the Security Council.
The UK and France both have permanent seats on the Un Security Council - the premier body for upholding world peace. There has already been one vote in the EU Parliament proposing that the UK gives up its Permanent Seat. Once the EU has a permanent seat in the Un Security Council there will be need no for the UK and France to keep their.
Slowly, slowly, little by little, the EU is eroding our power and our influence in the world. Being in the EU doesn't make us stronger or safer, it makes us weaker and having the EU, a supposed trading organisation sitting at the top of the UN Security Council is not going to keep us safer either.