Spasmodic stater motor engagement

[Landscaper]

When I turn the key sometimes noting happens, sometimes it starts perfectly (after waiting for glow plug light to exstinguish). If nothing happens I seem to push the key harder or return it and it starts perfectly.
This is a Mazda Bounty 2000. Is it a starter motor problem or somesome further up the electrical chain or other?
any ideas would be appreciated
Thanks, Ben

[sig]

sounds like the terminals in your ignition barrel

[bounty2001]

At the end of the ignition barrel is a plastic cap where the wires run into. these wear out and need to be replaced. Happened on my 2001 bounty cost 40 bucks from a wreckers. better than paying the huge amount the dealer wanted for a whole ignition barrel. Hope this helps.