I can only speak for Scottish Universities but the Honours degree equates to 240 ECTS points. Google to find out what you are worth in ECTS from a Swiss varsity, or your faculty secretary will tell you. To explain a little bit: It takes 3 years in the Scottish varsity system to get to the BSc (after completing secondary schooling at Higher level), and then you do either the Honours or the Masters for the 4th year. Some courses, like Pharmacy, do a combined Honours and Masters in the 4th year.
The 2:1 (or Upper 2nd class) part is a figure based on your average scores, but I forget what the % grades are - you can probably google it easily. In a simple version of A, B, C etc a 2:1 is a bit like a B+, where A is top grades throughout (ie a 1:1 or First class), then you'd have B+, followed by B- (2:1 and 2:2 respectively).
A Masters degree will be at least equivalent to the Honours though in terms of PhD entry. To do a PhD in the UK there is fierce competition. If you don't meet the standard criteria of ECTS points / Honours or Masters degrees you really need to show outrageously fantastic knowledge on the specific area of research with lots of SPECIFIC on the job (paid or unpaid) experience and at least a very good technical training to boot. Or just throw lots of money at them and hope.
No, seriously it is worth contacting the admissions people at the place you are interested and asking for some informal information on what would be acceptable for entry. There is a chance they will be flexible, but you gotta be top notch. Cream of the cream is what our 'bloke in robes' told us when we were all sat down being told how it is to be a PhD student and what was expected of us, they don't just let anybody in.........