Western ramping-fumitory is listed in the UK Biodiversity Action Plans (UKBAPs), and included in English Nature's Species Recovery Programme (SRP). As many new sites have been discovered in the last few years, it may be that this plant is spreading, especially as it seems to be a ready coloniser of recently disturbed ground.
It is known, however, to be irregular in its appearance. At some locations, such as Newquay and Lelant, it has been present ever since it was first discovered in the early 20th century, but other populations are considerably less reliable, or else are known to be in decline: for example, many populations on the Isles of Scilly have been lost, and it is now restricted there to small areas on St. Mary's, St. Martin's and St. Agnes.
The chief threat to the plant seems to be from the use of herbicides to control the growth of 'weeds' on field-borders and along roadside verges and Cornish 'hedges', and the general 'tidying up' of the waste ground and 'scruffy corners' so favoured by the plant.
The UK Biodiversity Action Plan
for this species is available at UK BAP