P102 CEEFAX 102 Sat 16 Apr 17:29/36         The Soviet embassy in London has protested about the "unjustified" expulsion of its second secretary from the United Kingdom. Mr Anatole Tchetnaev has been ordered to leave in retaliation for the expulsion from Moscow of a British air attache and a journalist. The Soviet embassy has called Britain's latest action "anti-Soviet" and without foundation. The BBC's correspondent in Moscow says the Russians will probably respond by expelling anothjt Briton, possibly a diplomat.