Despite the latest outbreak of feuding between the coalition partners over knife crime and free school meals, Mr Cameron said he continued to enjoy good relations with Deputy Prime Minister Nick Clegg.
"We have a working relationship because we are both committed to the long-term economic plan we have put in place for Britain to turn our economy round. We know that we have to make the coalition work for Britain," he told Sky News's Murnaghan programme.
While he acknowledged that there were "tensions and pressures" within the coalition, he added: "This coalition Government will last the course, will keep getting the job done and at the next election people can decide, I hope, for a Conservative-only government."
Mr Cameron insisted that he would not abandon his target to reduce the level of net migration into Britain to the tens of thousands by the time of the general election, despite growing evidence that it will not be met.
"We are doing everything we can to make sure that we can to deliver it.
"We should continue to do that," he said.