Andy Burnham hailed the 'best day of my life' today as he opened a temporary 'No10 North' office in Manchester. The PM gushed about the project after flying in on a Government jet from Scotland, where he attended the Commonwealth Games opening ceremony last night.He dismissed fears about the bill for the 'gimmick' and huge security operation, saying: 'What does it cost for everybody to troop down to London every time there's a meeting when you need to make an argument about something?' Mr Burnham is making great play of his decision to be based part of the week in Manchester, where his family lives and he used to be mayor.The so-called 'King of the North' wants to use the arrangements as a symbol of his drive to devolve power out of Westminster.However, construction has not even started yet on the site earmarked to become the premier's base in the city, and it will not be operational until 2032.Instead Mr Burnham is planning on using Heron House, an existing Government office in the centre that is used by GCHQ.Tory leader Kemi Badenoch labelled the PM's 'No10 North' as a 'gimmick', adding it's 'the actual decisions that are being taken that matter, not where you move people'.'I think this is a very interesting gimmick that the PM has pulled today,' she told broadcasters on a visit to Newport, south Wales.'Moving No10 to Manchester does not make decision-making any better. It's just creating another branch of the civil service in a different place.'Mrs Badenoch also accused Mr Burnham of 'acting as if he's still the mayor of Manchester', while - when asked if she would keep 'No10 North' if she became PM - the North West Essex MP said: 'I think if I was moving No10 to Essex, people would be raising an eyebrow.'The PM on Friday chaired a meeting of the National Economic Council at his temporary 'No10 North' office in Manchester, while he also held his first set of calls with leading business groups.Of the 28 attendees of the National Economic Council at 'No10 North' in Manchester, more than half - including the PM - are usually based at offices in London.