NEW DELHI: With several mega defence deals in the final stages now, including the hotly-contested $10.4 billion project to supply 126 medium multi-role combat aircraft (MMRCA) to IAF , defence minister A K Antony on Monday warned the top military brass against succumbing to corrupt practices or wrongdoings."Time and cost overruns apart, there is always the danger of falling prey to corrupt practices perpetrated by vested interests in the garb of aggressive marketing. I strongly urge you all to stand guard with resolve against any such overtures," said Antony, speaking at the IAF and Army commanders conferences here."You must strive to uphold sincerity, probity and fair play, even in your day-to-day administrative work...At times, vested interests bring about unnecessary pressure and resort to corrupt practices that can wreak serious havoc upon our security in more ways than one. We must resist such efforts collectively and resolutely in national interest," he added.The fighters in contention for the MMRCA project, which has seen high-voltage campaigns, are the American F/A-18 'Super Hornet' (Boeing) and F-16 'Falcon' (Lockheed Martin) Russian MiG-35 (RAC MiG), Swedish Gripen (Saab), French Rafale (Dassault) and Eurofighter Typhoon (consortium of British, German, Spanish and Italian companies).IAF chief Air Chief Marshal P V Naik, on his part, stressed on the "primacy of operations" and consolidation of the operational availability of weapon systems and sensors in the prevailing security situation. Army chief General V K Singh , too, emphasized the need for a high-level of operational preparedness.