JOIN USEndless underground building works have been blamed for the tiny topple and civil engineers say the problem is only getting worse, The Sun reported.
Built in 1853, the London tower is sinking into the ground more on the north side of the 315ft building. Its movements have led to cracks in walls in other areas of the House of Commons.
The top of the tower, which houses the historic Big Ben, is nearly one-and-a-half feet off centre.
John Burland, an emeritus professor from Imperial College London, said: "The tilt is now just about visible.
"I have heard tourists there taking photographs saying 'I don't think it is quite vertical' - and they are quite right.
"If it started greater acceleration, we would have to look at doing something but I don't think we need to do anything for a few years yet."
Compared to the four degree slant of Italy's Leaning Tower of Pisa, the clock tower slants at a fraction of that at 0.26 degrees. To lean over as far as its Italian counterpart would take another 4,000 years.