document: The Irish government suggested the formation of the group last week.
  But on Monday, DUP leader Arlene Foster said she had not been consulted over it and it appeared it would not go ahead.
  But Mr McGuinness has said he does not think "anybody should have a veto on a good idea".
  The Irish government government said it proposed the forum to enable groups to work on areas of mutual interest, such as trade, investment and health.
  The UK's decision to leave the EU dominated a meeting of the North South Ministerial Council on Monday attended by Arlene Foster and Martin McGuinness.
  Mrs Foster said the forum was not on the agenda.
  Instead, she said existing cross-border bodies would be used to work out the implications on the island of Ireland of a UK withdrawal from the EU.
  On Tuesday, Mr McGuinness said indications from "very senior civil servants within the [Irish] government" were that Taoiseach (Irish prime minister) Enda Kenny would go ahead with the plan.
  "I spoke to the taoiseach before the meeting of the North South Ministerial Council - he wasn't putting it as an item on the agenda but he stated very clearly to me that he still believed that it would be a very useful thing to do," he said.
  "I wouldn't be too exercised about the fact that there will be political elements who wouldn't be interested in attending.
  "The DUP will undoubtedly through different methodologies have their say in relation to all of it."
  He said he believed the idea of a forum would "get widespread support from most within the political process".
  Government ministers from Northern Ireland and the Republic drew up a list on Monday of priority areas they intend to work on to limit any potential damage of Brexit.
  Among the points was an agreement to conduct a "full audit" to "identify the possible impacts, risks, opportunities and contingencies" that the island could face.
  And the two finance ministers will "consider the issue of securing" further funding for regional development from the EU.
summary: A proposed cross-border forum on all-Ireland issues in the wake of the UK's decision to leave the EU could go ahead despite not having DUP support, Martin McGuinness says.