The organisations are asking the industry at what level the diseases should be managed.
The consultation paper asks whether controls should be reduced to a level that meets the minimum requirements set by the EU, but which may involve some continued disease spread within England and Wales; or whether a programme of increased activity aimed at reducing the presence and potential spread of the diseases should be implemented.
Minister for sustainable food, farming and animal health Lord Rooker said: "Despite five years of emergency action, P. ramorum and P. kernoviae have continued to spread, albeit slowly, in the nursery trade and the wider environment.
"We now know that they have the potential to cause significant harm to businesses and the natural landscape, and we need to decide on a policy for future management of the diseases."
He added: "I urge all stakeholder groups to consider carefully the science and economic information presented in this consultation and to contribute to the discussion on which approach is best for the natural environment, industry and the public good."
HTA business development director Tim Briercliffe said: "The HTA welcomes this formal consultation on future policy to tackle the two diseases. I urge all HTA members to give us their views to help formulate our response. The HTA will be making the consultation paper available to all its members."
The consultation ends on 10 October.
- For a copy of the consultation document, see www.defra.gov.uk/corporate/consult/phytophthora-ram-kern.