Fledgling trade body The Charter for Independent Estate and Letting Agents (CIELA) has described Purplebricks as the 'biggest enemy currently facing independent agents'.
The organisation has taken to its blog to explain why it has written a complaint letter to the high-profile hybrid agency.
The CIELA writes that it can think of no other single organisation 'doing more harm' to the reputation of estate agents than Purplebricks.
It also accuses the firm - which recently announced its intention to launch in the US - of misleading consumers into 'parting with money that they may well not be in a position to lose if their home fails to sell'.
The blog goes on to say that the CIELA has received legal advice suggesting that the agency's advertising may be in breach of consumer protection legislation.
The trade body accuses Purplebricks of taking instructions and up-front fees away from genuine agents that deserve them. It states that its goal is to increase market share for independent agents and this is therefore one of the primary reasons why it is targeting the agency founded by Kenny and Michael Bruce.
"A well-aimed sniper shot can slow even the biggest adversary," reads the blog posted on the CIELA website on Sunday.
"While a change to their advertising may not bring them down, it could do significant harm to their sales, which in itself would prove the advertising was misleading in the first place."
Purplebricks has declined to comment on the CIELA’s release.
The CIELA was formally inaugurated last week and is set for official launch in October.
Some 12 regional officers and an unspecified number of county and London borough officers will be appointed before the end of March.