(Reuters) -Russian prosecutors asked a court on Tuesday to sentence jailed Kremlin critic Alexei Navalny to an additional 13 years on fraud and contempt of court charges and to move him to a maximum security prison, Navalny’s spokeswoman said. Navalny is already serving a two-and-a-half year sentence at a prison camp east of Moscow for parole violations related to charges he says were trumped up to thwart his political ambitions. In a Twitter post, his spokeswoman, Kira Yarmysh, cited a judge of the Lefortovo court in Moscow as saying the sentence would be announced on March 22. Navalny used h…