My 1996 Polo Classic 1.6 has the clutch pedal stick to the floor even when i have taken my foot off. I replaced the clutch kit (and clutch cable) but the problem persists. further the car does not go off if the i apply the brakes without the clutch whilst it is in gear, like it is in neutral.

SOURCE: no pressure on clutch pedal

check your clutch pedal, probably leaked out somewhere

SOURCE: Clutch pedal occasionally sticks half way down

Make sure there is not an empty clutch reservoir (a lot like your brake fluid reservoir) up in the engine compartment, if it low or empty fill it.
as emissions wiz posted, a leaky master cylinder will keep leaking or losing pressure and needs to be replaced.

SOURCE: 1996 vw polo, won't/can't engage 5th gear.

Trans needs to be rebuilt. Or just not use 5th

SOURCE: Polo Classic 1.6 1999 model - Not idling, cuts out

look for a vacume leak that will cause a no idle condition it can consist of vacume lines or intake leaks good luck

SOURCE: brake lights stay on although the brake pedal is

You will probably find it is a problem with the switch on the brake pedal.
Get your self a cheap multi meter from an electronics store. Set it to meaure ohms. This is used to check if a connection is complete.

Take the wires off the switch on the brake pedal and test if the connection is open or closed. Push the pedal and check the connection again.

If the switch only had one wire then the negative connection is made to the body of the car. Put one probe of the volt against bare metal of the body somewhere and the other agains the terminal of the switch and test again.

This should tell you if the switch is broken. if the switch is good then you probably have a short circut somewhere between the brake lights and the switch. That is something has pinched or other wise broken the wire and it is touching metal of the car. You will have to follow the wires as best you can and look for damage.

Hope this helps