The dumping of small business minister Bruce Billson has “shocked” the small business community, according to the Council of Small Business of Australia.

COSBOA CEO Peter Strong told The New Daily that he welcomed the appointment of Liberal rising star Kelly O’Dwyer to the portfolio, but that Mr Billson’s demise was influenced by “Wesfarmers, Woolies and the BCA” who had “campaigned for 12 months to have him removed”.

Billson was widely regarded as pushing for reforms important to small business owners, particularly suppliers to the major supermarket chains Coles, owned by Wesfarmers, and Woolworths.

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Billson had championed new ‘unfair contracts’ rules designed to created a more level playing field between SME suppliers and large corporations, and an ‘effects test’ to prevent anti-competitive behaviour.

A short time before the collapse of the Abbott government, both reforms caused outrage among small business groups who accused the ex-Prime Minister’s leadership team of rolling Billson to appease corporate supporters.

On Monday, Strong warned the new Turnbull government against “going back to the Howard and Costello years, and governing for big business at the expense of small business”.

Incoming small business minister Kelly O’Dwyer is a former adviser to Peter Costello, and holds the seat of Higgins that Mr Costello vacated in 2009.

Another small business group, Independent Contractors Australia, dismissed claims O’Dwyer would automatically back the interests of big business.

ICA executive director Ken Phillips said he was “optimistic” about the appointment, but that O’Dwyer has a “test waiting on her desk, with the unfair contracts law”.

Phillips pointed out that O’Dwyer was intimately involved with key tax reforms made by former Treasurer Costello that allowed independent contractors to operate more as small businesses and less as “common law employees”.

He added: “Making Kelly assistant treasurer and small business minister is a sensible fit – that will give her direct control of the tax office, a primary area of concern for small contractors.”