In the Purdy case  UKHL 45, the House of Lords required the Director of Public Prosecutions to issue an offence-specific Policy setting out the facts and circumstances which would be considered in making a decision whether to prosecute a person for encouraging or assisting suicide (or attempted suicide) under section 2 of the Suicide Act 1961. The Policy has now been issued - see Crown Prosecution Service.
Section 2 of the 1961 Act was recently amended by the Coroners and Justice Act 2009 s.59. The essence of the offence is doing an act which is capable of encouraging or assisting another to commit suicide (or attempt suicide) with INTENT that the other is encouraged or assisted. The maximum sentence of 14 years imprisonment was retained.
The Policy document does not contain an exhaustive list of factors but 16 factors are set out which would tend toward a prosecution and 6 factors which would point against. The CPS emphasize that a "tick box" approach will not necessarily make the decision.
Looking at the Policy, it continues to be somewhat unclear whether a loving husband who purchases travel tickets for his wife, for whom life has become unbearable as a result of progessive disease such as Multiple Sclerosis, to travel to a certain clinic in Switzerland might be liable to prosecution. The Policy, whilst not changing the law, might make matters somewhat clearer in some cases but there would still be an investigation with no advance certainty as to the possible outcome. A prosecution might still follow. Only time and a tragic case will inform us further.