Lino on floorboards with gaps?

[pody]

Looking to lay new lino in kitchen for my cousin.

The existing floorboards have quite bit gaps between some of them 5mm or more sometimes and are not all exactaly level.
Whats the best thing to use was thinking of a layer of hardboard?

Never layer lino before, you you have some sort of sticky tape holding it down in line with the walls?

 

[^neo^]

id go for hardboard, and if you need it double sided tape around the edges. If the plinths come off from under the kitchen cabinets, then take them off before laying and tuck the vinyl under it, then you don't get any edges