The UK is not currently allowed to hold another referendum to join the EU. The 2016 referendum on EU membership was a legally binding vote, and the UK government has said that it will not hold another referendum until there is a significant change in public opinion.

There are a number of factors that could lead to a change in public opinion on EU membership. These include the UK's experience of being outside the EU, the performance of the EU, and the political climate in the UK.

If public opinion does change significantly, the UK government could hold another referendum. However, it is important to note that there is no guarantee that the UK would vote to rejoin the EU even if there was a second referendum.

The decision of whether or not to hold another referendum is a political one, and it is ultimately up to the UK government to decide. However, it is likely that the government will wait until there is a clear indication that public opinion has changed before holding another referendum.

Here are some possible scenarios that could lead to a change in public opinion on EU membership:

• The UK's economy performs poorly outside the EU.
• The EU makes significant reforms that make it more attractive to the UK.
• There is a change in the political landscape in the UK, with a new government that is more supportive of EU membership.

It is difficult to say when, or even if, the UK will be allowed to hold another referendum to join the EU. However, it is a possibility that should be considered as the UK continues to navigate its relationship with the EU.