Sources for elder statesman get in contact possibly underpinning a politician's greatness (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

First letters (sources) of E [lder] S [tatesman], inserted into LENS (possibly a contact = short for contact lens), after (below, in a down clue = underpinning) A + MP (abbreviation for Member of Parliament = politician).