Via Brussels - Cologne - Switzerland. Can be done reservation-free from Brussels.

I would recommend doing the journey in 2 days, with a night in Bern, Basel or Cologne for example (part can be done on scenic routes if wanted).

Otherwise it will be very long :

• RE Milano Centrale - Lugano 06:43 - 07:58
• IC21 Lugano - Basel SBB 08:02 - 10:56
• ICE Basel SBB - Köln Hbf 11:13 - 15:04
• ICE Köln Hbf - Bruxelles-Midi 15:40 - 17:35
• Eurostar Bruxelles-Midi - London St. Pancras 18:51 - 20:00 30€ mandatory seat reservation (book well in advance)

A 4,50€ optional reservation could be done between Basel and Brussels

Thanks both. For the brussels-cologne-swiss option I presume it includes an overnight somewhere?

For second option via lugano thanks for train suggestions. I'm thinking of this route but leaving milan evening of 25th and arriving london afternoon of 26th via bussels. 

There seems to be a no reservation routing but it involves a 4 hour stay in Basel station from 0100 to 0500. 

Milan 20.43 - Lugano 2158
Lugano 2202 - Basel 0102
Basel 0513 - Frankfurt Flughafen 0806
Frankfurt Flughafen 0831 - Brussels Midi 1135

There is currently plenty of availability for E* on 26/4 from Brussels.

Thanks Yorkie.  Yes that’s the route I was looking at.  I’m now having an issue with booking Eurostar on interrail site.  I had the same problem yesterday trying to book for London to Brussels on 10th.  All my credit card details were correct but it didn’t go through so I ended up booking on SNCB site.  Today the same thing is happening when I try to book the Brussels eurostar.  So frustrating!  I’ll have to use SNCB again I suppose.

Oh another question, will the train from Lugano to Basel wait for the connection from Milan since there is only 4 minutes?! 

Yes the connection in Lugano is guaranteed unless the first train has a big delay (15-20 min).

That's why I'd rather take an earlier train from Milan :

- 16:43, 17:43, 18:43. There is always the connecting train in Lugano to Basel (sometimes via Zurich). You then get to stay a little bit more in Basel. Much better than arriving at 1:00 and leaving at 5:00.

There is also a later connection from Basel :

- Basel SBB - Köln Hbf 07:13 - 11:04

- Köln Hbf - Bruxelles-Midi 11:42 - 13:35

And then the Eurostar :

- Bruxelles-Midi - London 14:52 - 15:59

Much more pleasant I'd say !

This is where I checked for E*. You will need a pass number from the Interrail tool to make the booking.

https://www.b-europe.com/EN/Booking/Pass#TravelWish

 

Thanks Yorkie.  Yes I got the pass number when I made my other booking yesterday.  I don’t understand why I can’t make the eurostar bookings via interrail site though - it’s so annoying.  Anyway I’ve managed it via the sncb website. 

Thanks Thibcabe.  I might look at an earlier train from Milan.

You're welcome.

As it's a reservation-free itinerary you can decide on the day. :)

Keep in mind to take the RE from Milan at xx:43, not the EC (mandatory reservation)

Sorry another question. How do you find these routes from milan to London without reservations? I've put in no reservations but they don't come up presumably because you need to reserve eurostar from Brussels (or paris). I did get the route thibcabe suggested but not sure howi did it! And I can't work out how to find the cologne route that someone suggested.  Thanks.

I use bahn.de or sbb.ch, they're the most complete and updated planners. DB Navigator or SBB app too

You can add "via xxx" on both routes (also possible to add how much time you'd like at every stop on bahn.de). If there is a R sign, then there's a mandatory reservation.

I split the trip in two or three as it's easier.

- Milan - Lugano

- Lugano - Basel SBB

- Basel SBB - Bruxelles-Midi via Köln Hbf

Thanks thibcabe. It clearly helps that your geography is much better than mine! I only know where I want to go (to visit friends) but don't know very well routes between one place and another! 

You can always use Google Maps for advice (I do it too) :)

The timetables aren't always up-to-date there though and you can't see the train compositions and such