British government borrowing will fall much less than expected because of slower economic growth, finance minister George Osborne said on Tuesday, erasing any room for error in the coalition government's deficit reduction plan.

Osborne said the independent Office for Budget Responsibility forecasts showed borrowing would fall to 79 billion pounds ($123 billion) in 2014/15, against a March budget forecast of 46 billion pounds.

For next year, public sector net borrowing is now forecast to total 120 billion years, up from the March prediction of 101 billion.

The structural deficit would be erased by 2016/17, Osborne said.

Osborne said the Conservative-Liberal Democrat government was still broadly on track to meet its fiscal goals, but had lost a one-year cushion previously programed into the fiscal strategy. ($1 = 0.6433 British pounds)

(Reporting by Matt Falloon, editing by Mike Peacock)