Ashton's predecessor Andy Robinson was criticised for taking a coaching role with the 2005 Lions in New Zealand.
England have a tour to Argentina pencilled in for the summer of 2009 and, two years out from the next World Cup, Ashton insists his responsibility would lie with the red rose.
He said: "I look at the way forward in three stages.
"In 2008 there is the Six Nations and the New Zealand tour, the next period is to the end of the 2009 Argentina tour and then we ought to be in a good position to move forward to the 2011 World Cup.
"There are short, medium and long-term objectives over the next four years.
"If I am still England head coach I will not be involved in the Lions. I will go to Argentina."
Ashton was officially reappointed as England head coach on Wednesday along with his two World Cup assistants John Wells and Mike Ford.
There were suggestions during the tournament that their working relationship was not always constructive but Ashton insisted they are the right team to take England forward.
Ashton is also looking to add new members to the staff, including a team manager to remove some of the burden from his shoulders.
"I don't want to be surrounded by yes men," said Ashton. "I think it would be foolish not to continue and let not only the team develop but the coaching team develop as well.
"I want a management team that I feel can take England forward. The game has got to move on and we have got to move on ahead of it.
"The playing squad and the management team have all got to buy into it."
Ford added: "I am pleased that we can build on what was achieved in France and I am looking forward to getting back together for the Six Nations.
"We have come a long way since the start of the year and now we have a chance to move England on to another level."