Ministers need to clarify their post-Brexit immigration aims, Migration Watch UK has warned.
The group said the Government can keep details of its strategy under-wraps, but should set out its broad objectives ahead of triggering formal withdrawal negotiations with Brussels next Spring.
Migration Watch UK is calling for visa-free movement to continue between the UK and the EU, except for workers.
The group wants skilled EU workers to need a permit similar to the one required for employees from outside the bloc.
And unskilled workers would not qualify for permits in a move which could cut the net flow to the UK by 100,000 a year, according to Migrant Watch UK.
Migration Watch UK vice chairman Alp Mehmet said: "Boris Johnson was right to make it clear that we are leaving the EU but we are not leaving Europe. It is important that we retain and develop our many links with Europe, while also tackling a significant part of the mass migration that has been so troubling for the British public."
A Home Office spokesman said: "Government has been clear that, as we conduct our negotiations, it must be a priority to regain more control of the numbers of people who come here from Europe. It would not be right for us to give a running commentary on negotiations."