1998 Ford KA oil leak and car now wont start

That sounds bad ,it could be a seized engine ,one of your pistons has jammed in the bore due to lack of oil.You can only sort the leak top up with oil and try turning by hand .

I agree with the last post- The oil leak may be due to broken internals of the engine damaging the sump but without seeing it, I would not know. The smoke could be down to lack of oil in the sump (these engines do use oil with higher miles especially) or down to general engine wear (valve guides/piston rings etc. The cheapest solution may be to get a second hand engine from a scrapyard (easily available) or a recon unit.The type of engine is called ENDURA E 1299cc. This engine was also used in some Fiestas from 1996-2002. Hope this helps, best of luck.