Many thanks for your quick reply! I have managed to get the switch out and I will explain how I did it. The lugs you mention are not accessible with the switch fitted.
This is a 25 year old machine and as such plastics are likely to be very brittle. I did not want to force anything in case the panel broke.
What I did was warm the panel where switch is with a hairdrier for a few minutes to make the plastic more flexible. I then carefully prised the switch out using a screwdriver.
It came out cleanly this way. I suspect without the warming the plastic would have broken.
I warmed things again before push fitting new switch.
Everything is all good now and my 'vintage' washing machine is back in action.