Gerry Brownlee says a "conspiracy theorist" claim left him no choice but to cancel a traditional drinks event in Christchurch.

Earthquake Recovery Minister Gerry Brownlee has cancelled his own party because of a "conspiracy theorist" claim of favouritism in the rebuild.

Since 2012, Brownlee has hosted drinks in Christchurch the week before the All Blacks play a test in the city, inviting members of the media, business and sports communities. The event was sponsored by Fletcher Construction; the Canterbury Earthquake Recovery Authority (Cera) managed the invitations.

Invites to this year's drinks, ahead of the All Blacks-Argentina test on July 17, were sent out this week, before Brownlee abruptly withdrew them.

In an email to invitees, Brownlee said one recipient had responded "by overtly [implying] an improper relationship between Cera, Fletcher Building, and by implication me".

He labelled the insinuation "unacceptable" and cancelled the drinks.

The disgruntled recipient was a member of a consortium that unsuccessfully bid for the $800 million residential development of the north and east frame precincts, Brownlee said. The tender was this month awarded to a subsidiary of Fletcher Building, Fletcher Residential.

Brownlee "strongly [refuted]" any link between Fletcher's sponsorship and the successful tender.

"This is not the first time conspiracy theorists have tried to suggest something along these lines. Personal attacks of this nature, without foundation, and as a kneejerk reaction to non-selection as a preferred tenderer, is extremely disappointing.

"Unfortunately this nonsense usually ends up in the media, arguably harming all parties' reputations in the process of refuting it. Rather than let that happen this time, I've decided it's simpler for everyone that I cancel the event."

Brownlee's email was arguably the only reason the matter did not stay private. The mailing list included several Fairfax Media employees.

Because Fletcher had offered "at relatively short notice" to sponsor the event in 2012, "we've always considered it good manners to have a right of first refusal to re-host", Brownlee said, despite interest from other businesses. The first drinks, in 2012, came shortly after Fletcher won the tender to manage the Earthquake Commission's home repair programme.

There were three unsuccessful tenderers for the east-north frame development:

- a joint venture of large home builder Mike Greer Homes, wealthy businessman Philip Carter's Carter Group, Ngai Tahu Property and Canterbury Community Trust.

- Todd Property group, which owns the Pegasus town development north of Christchurch.

- NewUrban Group, lead by Bert Govan and John Fairhall, newcomers to property development, with Chinese partner Huadu.

In addition to the home repair programme, Fletcher building and its subsidiaries have been awarded more than $1 billion in building contracts in Christchurch: the east-north frame development, a 200-home development on city council-owned land in Welles and Colombo streets and the 89-home Awatea-Carrs Rd development in Wigram.