Union Management Agreement - Public Sector Undertaking

I am working in a public sector undertaking as a Senior Assistant. The total strength of this company, both executive and non-executives, is 1500. My query is related to management. The competent authority of the company changed all old union management agreements related to basic facilities like conveyance, medical, canteen, and compensation grounds without discussing with the present trade union. Please confirm whether the top management can take this type of step without completing any agreement with the present trade union and if they are violating the trade union rights or not.

Could you also advise me on the latest books related to trade union rights in public sector undertakings?

Hoping for an early reply.

There is no information in the post about the type of settlement, whether it was a proper settlement signed under section 18(1) or 12(3) of the Industrial Disputes Act, 1947, or a mere memorandum of understanding informally signed by the parties. It is unclear whether the conditions of service in the settlement have been revised unilaterally by the management when it is in effect or after its expiry.

Any trade union, whether registered or unregistered, can support the cause of the workers if it has sufficient representative character and is authorized by the workers before the management for redress. In case of failure, the union can approach the Conciliation Officer by raising a formal industrial dispute under the Industrial Disputes Act, 1947.