A Home Office licence is not required to grow or harvest opium poppy (papaver somniferum). A licence is only required when the opium poppy is processed in any way.
The Home Office does not routinely estimate the proportion of acquisitive crime or sex work committed which was motivated by the need to raise money for illegal drugs. Drug use, offending, and sex work are often covert activities and the relationship between them can be complex, thus such estimates are likely to be subject to large uncertainties.
The Department has previously commissioned research that shows proportions of drug treatment seekers and police arrestees who have reportedly committed acquisitive crime in order to buy drugs:
Nearly a quarter (22 per cent.) of a nationally representative sample of drug treatment seekers reported offending in order to buy drugs in the four weeks before interview.
Source:
Home Office Research Report 3
http://www.homeoffice.gov.uk/rds/pdfs07/horr03c.pdf
12 per cent. of a sample of arrestees said that they had committed crime in order to buy or get hold of drugs. This was much more likely among those who took heroin or crack cocaine once a week, 50 per cent. of whom had committed crime to get drugs compared to 4 per cent. of those who did not take heroin/crack weekly
Source:
Home Office Statistical Bulletin 12/07
http://rds.homeoffice.gov.uk/rds/pdfs07/hosb1207.pdf
There are a number of research studies that have shown that prostitution, especially street based prostitution, is linked to illegal drug misuse. A Home Office evaluation of five projects that aimed to provide support to help women involved in street prostitution to exit, indicated that around nine out of 10 women involved in street based prostitution used drugs, although the findings do not indicate whether the sex work was motivated by the desire to buy drugs
Source:
Home Office Research Study 290
http://www.homeoffice.gov.uk/rds/pdfs05/hors290.pdf