I'm installing a second hand fully integrated slimline dishwasher in my kitchen. Is it sufficient to secure it only to the worktop, or should I attach it to the side of the cabinets it sits between as well?

Securing it to the worktop would be fine plus I would recommend cutting a piece of the old worktop to the size of the base of the dishwasher and placing it where the dishwasher is to be then push the dishwasher on top of it as if you plan on tiling the floor or have vinyl flooring then when you have to remove it in the future it will be so much easier .

Thanks for that. The machine in question is a Beko DW 450. According to the installation manual ( just a series of diagrams with no explanation) the height between the bottom of the legs and the top of the unit is adjustable between 820 and 870mm. However, it also says that the legs should not be set to more than 50mm height. Which ,makes it impossible to raise the total height to 870mm. I'm a bit puzzled.

The feet extend about 3 inches max but i would defo use worktop under it as the more you unscrew the legs the more unstable it becomes

It's going to be a while before I can install it fully under the counter and attach it. Is it safe to use it freestanding as a temporary measure?