The cash allocated for Pilgrim hospital will increase the size of the department and include a new waiting room.
Members of the public invited to join campaigners at the socially-distanced gathering next month.
Lincolnshire has seen a rise of 18 positive coronavirus cases in the last three days.
The Meres Leisure Centre will reopen today (Monday) following a lengthy closure forced by the Covid-19 pandemic.
Four new cases have been reported in Greater Lincolnshire.
Four additional positive Covid-19 cases have been announced today, but no new deaths.
No more deaths are reported in the county.
A county public health chief is encouraging people to 'make the most' of summer months in case Covid-19 cases rise from the autumn.
More than two weeks without a fatality ended at the weekend with news of a death in a ULHT hospital.
Clinics are set up in grounds of Moy Park in the town.
Campaigners write to MP and health bosses to highlight problems people are having following the downgrade of A&E.
Infection rates and the number of people becoming ill in the county are low, says health boss.