One of the candidates in the Scottish Labour leadership race is urging the party to come out in favour of the construction of new nuclear power stations north of the Border.  Tom Harris, the MP for Glasgow South, said that the party should put aside its equivocation on the issue and recognise that nuclear generation was the only way of ensuring that any future energy gap was filled.  He told a meeting of Labour students that increased nuclear power was also the best way of meeting targets for cutting carbon emissions. He said: "We are in love with renewables and while renewables have an important place in the energy mix, they cannot meet all our energy requirements.  "If there is scepticism about nuclear power it is because politicians in the Labour party and in other political parties have not made the case. [It] is safe, environmentally-friendly and efficient." More than 300,000 ballot papers are being sent out this week for the Labour leadership contest. Members of affiliated trade unions and other organisations can also play a part in choosing the new Scottish Labour leader.  Colin Smyth, the party's Scottish general secretary, said the race to succeed Iain Gray was "not just an election for party members, but party supporters".  Of the three candidates for the post, Johann Lamont, the party's current deputy leader, has secured the most nominations, winning the support of 27 MSPs, MPs and MEPs.Her rivals Ken Macintosh, MSP, and Mr Harris are backed by 26 and 13 elected Labour politicians respectively.  The candidates will take part in a hustings in Edinburgh tonight.