Shadow Transport Secretary Maria Eagle has told ITV News investment in the rail network is needed now, not in 2014, when the Government plans to begin its schedule of improvements.
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Coal's share of the power mix had fallen to 7%, while wind climbed to new highs to provide 15% of the country's electricity.
State Department spokeswoman Heather Nauert said Pence "was ready to take this opportunity."
Opposition activists said government forces have brought in more reinforcements in recent days.