First off I'd try cutting them off at ground level. If they do decide to regrow you win - if not try planting something reasonably short lived near them fill the space while giving to give them time to rot down

A drink of diluted beer helps the stumps to rot faster, especially organic beer. One smallish can in a 7 liter watering can, drenched over a square meter on and around the stump. Also good for deducing the tuft of straw left behind when trimming ornamental grasses. Sadly it works too slowly on really big stumps, though--say, 10 cm thick or more.

Thanks Guys. Have actually just watched a YT video on well anchored shrub removal and I happen to have all the correct tools so gonna give it a go...when it stops raining but that will also help, wet soil gives up better than dry :]

Hebe once cut down are fairly simple to get out, they tend to have a very fibrous root system, and are easily grubbed out, I always use a good sturdy mattock, strike it round the stump to break up the root fibres then go in deep on one side and if needed leaver it with an iron bar, it’s that simple but of course a little strength is needed, don’t go and injure yourself by going bull at a gate just pace yourself, just to add shove an iron bar in and place a large brick etc at the base for extra leverage, good luck and let us know how it went.

Hebes out, enlisted some brute strength! Scrape away at peripheral roots and main root levered out. Thanks all.