The Canberra Times reports  a man who smashed century-old headstones at an iconic church in Canberra's inner north drunkenly phoned his ex and said he'd ''make it up to the people he f---ed over''.

James Dudley March yesterday pleaded guilty to damaging 14 headstones in a churchyard next to St John's in Reid, the territory's oldest church.

The 24-year-old, who was charged with damaging property worth more than $1000, also admitted an unrelated burglary offence.

He will now be sentenced in the ACT Supreme Court at a later date.