The EU interfering in the UK election is very understandable and in their interests where they want to keep our memberships fees rolling in to subsidise mainland Europe, especially French peasant farmers. After all, there is a long history on this, from making people vote in referendums until they get the right result to deposing a democratically elected government in Greece and the prime minister in Italy with their own 'officials'.
The reality is that there are no leaving penalties in any of the treaties as is normal for this type of agreement. The advantage the EU has is that an all-out trade war will hurt us more in the short term, but the EU much more in the long term as we substitute their food and goods with cheaper ones from the rest-of-the-world. French farmers will be very quickly screaming louder than their stuffed pigs.

and the EU won't like the drop in UK car sales. The most likely case will be resorting by both sides to WTO import tariffs, which will hit Europe much more than us. This averages 3.5%, with the exception with much higher tariffs being cars and food. With the world awash with cheap food, replacing this for cheaper suppliers will be very easy. For example, Spain will lose the UK salad market where Africa will be much cheaper.

How good our leaving terms are will depend upon where it is democratically member governments or the unelected EU has the upper hand. The EU's aim will be to punish us as an example regardless of the cost to them and us, as unlike the member governments they never have to face the ballot box!
