A senior union leader has warned the Government that talks aimed at averting strikes were now in "jeopardy". The criticism from Dave Prentis, general secretary of Unison, followed an expected announcement from ministers that public sector workers will have to pay up to £3,000 a year more to keep up their pension schemes. Mr Prentis added: "These talks are being put in jeopardy by the crude and naïve tactics of Government ministers who don't seem to understand the word negotiate."