The Christchurch earthquake rebuilding that is driving New Zealand's strong economic and lending growth hit a stumbling block on Monday when the Christchurch City Council was stripped of its accreditation to issue building consents.The government-backed body, International Accreditation New Zealand, formally revoked the council's accreditation after repeated warnings about slow consent issuance and poor paperwork.Standard & Poor's then downgraded the Christchurch City Council's long-term credit rating by one notch to A+.The crisis over building consents also claimed the scalps of council chief executive Tony Marryatt, who was put on indefinite leave and replaced by an acting CEO, and mayor Bob Parker, who announced late on Friday that he would not stand for a third term in the council elections being held in October.The Government also intervened on Monday to appoint Douglas Martin as a Crown manager for the city council's consents department. "The Crown manager will have the authority to direct the Council to take actions he considers necessary to resolve the Council's on-going issues with building consents," said Earthquake Recovery Minister Gerry Brownlee.Developers, contractors, home-owners and politicians have been complaining for months about delays in consents and concerns that consents may have been issued that will allow unsafe buildings to be constructed. Delays over insurance disputes and struggles finding reinsurance had previously held up the rebuild.Last week, Brownlee called for an audit of all recently constructed buildings to ensure they do not have to be demolished and rebuilt. The widespread concerns culminated on Saturday when Riskpool withdrew its professional indemnity insurance protection for the council's building consents, saying reinsurers had expressed concern over the status of consents.Standard & Poor's said: "The downgrade reflects the emergence of significant issues regarding CCC's building consenting process, and the departure of multiple key staff."The rebuild is expected to generate NZ$40 billion of construction and repair work over a decade, helping to generate around a third to a half of New Zealand's economic growth over the next four years. New Zealand's economy is forecast to grow around three to four per cent over the next year, outperforming growth in Australia.