Nick Clegg is to embark on three days of door knocking in his Sheffield constituency after a shock poll showed he is on course to lose his seat at the general election. The Deputy Prime Minister is trailing Labour by 2 per cent in his formally rock-solid Lib Dem constituency, Sheffield Hallam. Mr Clegg won his seat in 2010 by a huge margin – scooping up more than 50 per cent of the vote. Today he insisted: 'We are going to win Sheffield Hallam. We are confident but not complacent.' Lib Dem leader Nick Clegg is trailing Labour by two points in his formally rock-solid Lib Dem constituency in Sheffield, a poll revealed this morning . Aides said he would be out knocking doors on Friday, Saturday and Sunday. But a poll by the Tory peer Lord Ashcroft shows 36 per cent of voters in Sheffield Hallam are now planning to vote for Mr Clegg's Labour opponent Oliver Coppard - compared with 34 per cent who said they would support the Deputy Prime Minister. The revelation was included in the latest round of polling of marginal constituencies which could help decide the next election. These include one Tory-held and seven Lib Dem constituencies. The polling suggests that the Lib Dems will hold on in four seats, reinforcing the party's claim that they will do much better than national surveys suggest. On a national level, a poll of polls puts Labour and the Tories neck and neck on 34 per cent, with Ukip on 13 per cent and the Lib Dems trailing on just eight per cent. A spokesman for Mr Clegg said the Lib Dems were confident of winning Sheffield Hallam. He said: 'We are never complacent, we don't take any votes for granted but we are confident on winning because Nick's been the local MP there for ten years, he's got a record in Sheffield that we are happy to defend and his constituents appreciate'. Fourteen-month-old Sophia O'Driscoll met Mr Clegg today as he visited Play Town soft play centre in Bishopbriggs in East Dunbartonshire . Mr Clegg was promoting his policy to treble paternity leave to six weeks with Lib Dem minister Jo Swinson (right) The Lib Dems say internal polling shows an average 9 per cent increase in the vote for their party when candidates are named, but could not say whether this was true in Mr Clegg's case. The spokesman said failing to put the candidates name down, as on the ballot paper, would not yield an accurate result. He said: 'Nick is extremely well known in Sheffield Hallam, and hugely well respected. He has a large personal vote and has ‎delivered consistently over the last 10 years. Labour are talking a good game but they seem to be measuring the curtains already when they are not ‎going to be successful.' Since 2010 there have been 16 local elections in the constituency of which the Lib Dems have won 14. In the last set of local election sin 2014, the Lib Dems won in 4 out of the five wards in Sheffield Hallam. Across the constituency the party got 38.7 per cent of the vote, Labour got 23.6 per cent and the Tories came fifth on 10.7 per cent. Mr Clegg spent today campaigning alongside East Dunbartonshire Lib Dem MP Jo Swinson, including a visit to the Thomas Muir coffee shop in Glasgow . Despite Lib Dem confidence, Labour  claim its candidate in Sheffield Hallam could topple Mr Clegg after building up a 'formidable' campaign team. Tom Watson, Ed Miliband's former election coordinator, said: 'This seat is winnable for Labour. I have never encountered such animosity on the doorstep against an incumbent MP - particularly one as high-profile. 'There are two issues that come up time and again: his position on tuition fees and Sheffield Forgemasters, which has not been forgotten.'
Lib Dem leader is trailing Labour in Sheffield Hallam constituency .
Deputy Prime Minister won his seat in 2010 with more than 50% of the vote .
Revelation included in latest round of polling in marginal constituencies .