Ministerial reshuffle: Alistair Carmichael replaces Michael Moore as Scottish Secretary Alistair Carmichael was promoted to the post of Scottish Secretary today as a reshuffle of ministerial posts got underway. He replaces his fellow Liberal Democrat Michael Moore in the Cabinet less than a year before the referendum on Scottish independence. His appointment signalled that the Coalition wants to adopt a more aggressive approach to Scottish First Minister Alex Salmond. Mr Moore took a conciliatory approach to the independence debate. Mr Carmichael, the MP for Orkney and Shetland, was previously the Lib Dem chief whip. In a letter to Mr Moore, Nick Clegg said a "different experience" was required in the run-up to the on referendum on September 18. The Deputy Prime Minister left the door open for a possible return to the front bench for Mr Moore in future, telling him he had "no doubt there will be an opportunity for your talents to be deployed" in government again. Meanwhile, Sajid Javid moves up a rung to replace Greg Clark as Financial Secretary to the Treasury, while Mr Clark moves to the Cabinet Office to become Cities and Constitution Minister. Alistair Burt, who was a minister in the Foreign Office with special responsibility for the Middle East, has left his job. He has been replaced by former sports minister Hugh Robertson. He tweeted: "Standing down today. The last 3 1/2 years have been a pleasure working on an extraordinary portfolio with talented people. Thank you all! The Foreign Secretary, William Hague, tweeted that Burt was "the best UK Middle East Minister in a long time (who) built stronger ties across the region amid many crises." Mike Penning is leaving the Northern Ireland brief to become a minister at the Department for Work and Pensions. Nicky Morgan has been promoted from assistant whip to Economic Secretary to the Treasury, No 10 confirmed. Three Conservative ministers have already announced their resignations ahead of the reshuffle. Simon Burns has stepped down as a transport minister to launch a bid to be a Commons deputy speaker, while Cabinet Office minister Chloe Smith and deputy Tory chief whip John Randall are also quitting. The departures increase the scope for Mr Cameron to bring in fresh faces to his top team - which is tipped to include a number of young and female MPs. But he is also losing one in the shape of Ms Smith, who was only elected to the Commons in 2009 at the age of just 27 and was quickly promoted to the ministerial ranks. In his letter to Mr Moore, Mr Clegg said: "As we discussed when we spoke on Friday, I believe we now need to draw on different experience in the final year running up to the referendum itself and I am keen that, just as we have benefited from your formidable skills over the past three years, that we take advantage of other experience within our ranks during this period. I am immensely grateful for all the work you have done at the Scotland Office and for the very significant contribution you have made to the first coalition government in 70 years. I have no doubt that there will be an opportunity for your talents to be deployed in government in the future. Mr Moore replied: "This has been, and will continue to be, a hugely important time in Scottish politics and that has made it a challenging and rewarding time to be Secretary of State for Scotland." He added: "In leaving the Scotland Office I am pleased Alistair will be succeeding me. As a good friend and long-time colleague, I believe he will do a superb job. I wish him all the best. Number 10 also announced Andrew Robathan left his role as Armed Forces Minister to become Northern Ireland Minister.