So welcome!

[NewAmerica]

What is the grammar of the expression "So welcome!" here? I guess:
1) So welcome to stay inside the EU.
2) So welcome the deal!
3) So (you are) welcome! (Saying to the bus goers onboard who response to the speaker)
4)...?

Which one is correct?

*****************
The message is the deal we've got is the best deal... Inside the European Union!
Inside the EU...So welcome!

Source: from a YouTube video titled
Day 1 - Bollocks to brexit Bus Tour

 

[Uncle Jack]

I would suggest that the subject and verb have been omitted and that it means "Inside the EU, we are so welcome".

 

[NewAmerica]

Welcomed by whom? By the rest of the world?

Thank you.

 

[Uncle Jack]

No, by the rest of the EU. If you are welcome in a place, the welcome is from the other people who are there or, if appropriate, the owners, management or proprietors.

 

[heypresto]

Who says this, and to whom?

Given the title of the video, I'm wondering if the speaker is welcoming the viewer (or some listeners in the video) aboard the bus as they head off on the tour.