How to check if door switch is faulty on Hotpoint Aquarius 1100?

The door switch on our Hotpoint Aquarius 1100 washing machine has been a bit difficult to operate for some time and we often had to slam the door to start the machine.
Now it wont work at all.
I removed the switch mechanism but left it connected to the leads.
When I reconnected to mains all three of the contact points were live but operating the sliding switch does not seem to change anything. Using a meter on the disconnected switch indicated that there does not appear to be any connection between the contact points whether the sliding switch is out or is pushed in against its spring.
Does this indicate a new switch is required?
The door indicator light normally oerates but not since this fault developed.
We are in France so cannot easily call out a repair man. Thanks in advance for any help.