Canterbury Cricket says plans to develop a first class oval in Hagley Park, Christchurch, are not aimed at commercialising the park.
And it says the ground will be needed if Christchurch is to host World Cup matches in 2015.
Chief executive Lee Germon says the oval is already used for club cricket, but it could also attract international matches.
The venue would require the construction of grass banks and a pavilion.
But, out of 180 proposed days of use, he says a maximum of 20 would involve entry being charged.
However, the Save Hagley Park group says this amounts to commercialisation by stealth.
It says the venture would set a precedent for anyone to ask for any project within the park. It fears that Hagley Park could be closed to public use within 10 years if the proposal goes ahead.