Formal invitation to Government bodies

Below is a sample of my invitation letter
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(Logo)

xxx Council
requests the honour of
Your Excellency xxx
Honourable Prime Minister xxx
Dr xxx
and
Premier xxx of xxx
presence at the
xxxxxx Ceremony
on Wednesday, 31th March, 1900
4 o'clock, P.M.
at xxx(Insert Location Here)xxx

Public reception will Dinner is organized after
commence at 4 P.M. the ceremony at 8 P.M.
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Does this format seems ok?
Or shall I write it properly in a letter format?