( 1 ) THIS writ petition is filed by 21 employees who were initially appointed by the management of the Andhra Pradesh co-operative Oilseeds Growers Federation limited (for short apoilfed ), the 1st respondent herein and who are presently serving in the establishments of Sri vijayavardhani Co-operative Oilseeds growers Union Limited, Beechpally and sri Krishna Devaraya Co-operative Oilseeds growers Union Limited, Filer, respondents 2 and 3 respectively. The petitioners have sought for a writ of mandamus declaring that they continue to be the employees of the APOILFED only and not of any other body or employer including respondents 2 and 3, and that they are entitled to all the benefits of employment under APOILFED including seniority and parity of salary and service benefits on par with the employees who are presently serving in the establishment of APOILFED.

( 2 ) THE background facts that led to filing of the writ petition be stated briefly as under : APOILFED, the first respondent herein, was established during the year 1983 with financial assistance of National Dairy development Board (for short nddb ) under the scheme called "operation Golden flow" with an objective of increasing the productivity of edible oilseeds in the andhra Pradesh State to bridge the gap between demand and supply of edible oils. To achieve the goal, the APOILFED initiated organisation of Primary Oilseeds Growers societies at the village level and recruited field staff for organising the societies giving training to the farmers on improved package of practices. For the purpose of production of edible oils, the APOILFED undertook the responsibility of organising and developing Oilseeds Co-operative societies and to manage them if necessary and train them to purchase and process locally produced edible oilseeds from the growers and generally to undertake all measures for increasing the productivity of such oilseeds.

( 3 ) THE petitioners were recruited in various cadres in the establishment of apoilfed in the years 1983, 1984 and 1985 after going through the recruitment procedure prescribed by the Service Rules. The respondents 2 and 3 Unions were not in existence when the petitioners were recruited. The respondents 2 and 3 Unions were formed to give effect to an undertaking given by the Government of Andhra Pradesh to the NDDB in an agreement dated 19-3-1987. In terms of the said undertaking, the Government was obliged to form oilseeds Growers Co-operative Societies and their Regional/area Unions and a State level Oilseeds Growers Federation to enable them to function in accordance with the approved bye-laws, to provide government guarantee for the repayment of long term loan advanced by the NDDB to the APOILFED. The APOILFED was adopted as the State-level Oilseeds Growers federation. After the above agreement in the year 1987, the Government of Andhra pradesh acting through APOILFED and the District administration formed several primary Oilseeds Growers Co-operative societies, as a first step in the establishment of three-tier pattern contemplated in the undertaking given by the Government of andhra Pradesh to the NDDB. Such Primary co-operative Societies came into existence between the years 1987 and 1990. After the primary Co-operative Oilseeds Societies were formed, the next step in the implementation of the undertaking was carried out by forming the Regional/area unions between the years 1990 and 1992. Steps were taken to organise the Unions which would have administrative control over Area Office/field Offices, and the administrative control over those offices were made over to the Unions. Respondents 2 and 3 are the two Unions formed by the apoilfed to give effect to common purpose mentioned in the agreement dated 19-3-1987 executed by the Government of andhra Pradesh in favour of the NDDB. An Office order dated 2-5-1992 was issued by which the second respondent Union was allotted the Central Processing Unit, beechpally