Thomas Cook is among the stocks lifting the travel and leisure sector higher. The tour operator has echoed bullish comments from rival TUI and reports a steady increase in bookings for the Summer as consumer confidence recovers.Elsewhere in the sector, investors have an appetite for Gourmet Burger Kitchen owner Clapham House after a trading update. The company expects to open only two restaurants in 2011 and focus on Gourmet Burger Kitchen.Shares in Mitchells & Butlers, which yesterday said it is to focus on food and will likely exit some of its best known drinks chains including All Bar One and O'Neill's, are also higher.Ceres Power is among the stocks draining on the alternative energy sector.The fuel cell technology developer's interim loss grew to £5.9m from £3.3m a year earlier as revenue slumped 39%, blamed on the £2m Alpha milestone completion payment from British Gas last June being recognised as revenue when earned, based on costs incurred over the Beta and Gamma phases. Top performing sectors so far todayElectricity 6,553.96 +3.08%Travel & Leisure 4,848.60 +2.18%Media 3,675.34 +1.93%Chemicals 5,191.97 +1.76%Banks 5,187.73 +1.73%Bottom performing sectors so far todayAlternative Energy 6,084.99 -2.25%Mobile Telecommunications 3,410.00 -1.13%Forestry & Paper 5,038.84 -1.10%Industrial Metals & Mining 6,551.41 -0.69%