You're right about consultation, but there's a sneaky trick to get around it.
Simply tell the affected people they've been selected for voluntary redundancy, which comes with a much more attractive severance package. If they don't volunteer, you then forcibly make them redundant -- with a less attractive package, they can then enter into consultancy if there are enough of then.
When this happened to me, 30% of the company was laid off, everyone took the "voluntary" package, no consultancy took place.
Simply tell the affected people they've been selected for voluntary redundancy, which comes with a much more attractive severance package. If they don't volunteer, you then forcibly make them redundant -- with a less attractive package, they can then enter into consultancy if there are enough of then.
When this happened to me, 30% of the company was laid off, everyone took the "voluntary" package, no consultancy took place.