Employees of major ports can be treated as govt. employees ?

I am working in Mumbai Port Trust. All Major ports are controlled by Ministry of Shipping by a act called "Major Ports Act". Chairman, Dy. Chairman, CVO are appointed by Central govt. and usually from cadre services (IAS,IRS ----). Even Board of Trustees are appointed by Central Govt through notification in gazzette. All service rules applicable to central govt. employees applies to us also. But still we are denied the benefit of IT exemption on the amount of encashement leave received at the time of retirement. Even our pay structure is similar to central govt employees and wage settlement pact is based on pay commission formed by govt. from time to time.

So, why we are not treated as govt. employee ? Is there any point in refering our case to IT tribunal ? Can we claim back rebate at the time of filing IT return ?

pl. guide.