It represents another delay in the Scottish Government’s timetable, that originally estimated that the bridge would be open last December.
The SNP had repeatedly pledged that the bridge would be completed on time, but this is already the second delay to the completion date that has been announced.
It also comes after the Forth Road Bridge was shut twice over the past few months, causing huge delays to the thousands of commuters who use it every day.
Questions are now being asked about when Keith Brown knew of the delay, with many of those involved in the project having predicted further delays in recent weeks.
Scottish Conservative transport & infrastructure spokesman Liam Kerr said:
“This delay will come as a huge blow to the many commuters who travel across the Forth every single day.
“They have already had to deal with massive disruption over the past two months due to closures on the current Forth Road Bridge, and now we learn that the Queensferry Crossing is months behind schedule.
“The SNP assured us that this project would be delivered on time, but these promises have proven to be worthless as, once again, we see the completion date slipping.
“It is simply unacceptable, and the economy secretary needs to explain why this delay has occurred and what the Scottish Government are going to do to ensure the new timescale is kept to.
“There are also underlying questions about how long Keith Brown has known about this issues. Many contractors had been hinting at delays in the previous few weeks, so if they knew it was going to be delayed, why didn’t the minister?
“It points to someone who is either hopelessly out of touch with this project, or someone who was waiting for a busy news day in order to bury bad news.”