There are currently 39 male and five female chief constables in England and Wales. The data currently available are for ACPO ranks and are previously been published in the Home Office Statistical Bulletin, Police Service Strength in England and Wales 31 March 2006 (13/06), which is available in the Library of the House and can be downloaded from:
Table 4 in the bulletin contains the number of police officers in each force in England and Wales broken down by gender and rank. Promoting policing equality and diversity is a matter for the National Policing Improvement Agency (NPIA) working with the police service. I understand from the NPIA Chief Executive that there are a number of programmes geared to encouraging progression of staff within ACPO ranks including, HPDS ( High Potential Development Scheme) and NSCAS ( National Senior Careers Advisory Scheme).