But this morning, the analyst turned (slightly) bullish, saying it was "less cautious" about housebuilders' share prices.
But in a note published today, Campbell backtracked on that, saying although he had been right about housebuilders' share prices, it was for the wrong reasons.
"The shares have underperformed with Brexit and London the main culprits," he admitted.
"Margin pressure remains a threat [borne out in last month's construction figures] and not all Brexit risks are priced in, but valuation is much more accommodating.
"We remain more cautious than most but see little downside in the sector now. We upgrade Barratt and Persimmon to Hold, leaving only Taylor Wimpey at sell."
Why the sudden change of heart? Although house prices in central London have been hit as a combination of the impending EU referendum and new rules over stamp duty began to take their toll, that the effects of those across the rest of the country have been minimal.
"Valuations across the sector are now much less stretched following a 13 per cent fall since our November note and 17 per cent from December highs," said Campbell.
"The sector has been weak as Brexit and prime London worries depress shares. We think the sector would now rally on a Remain vote, but may fall further if rates rise and GDP slows in the event of a Leave decision.
"Weakness in prime London is unlikely to ripple out in the absence of a hard Brexit, but affordability is still a constraint to house prices. Recent weakness in Persimmon’s sales rates also needs monitoring."
Campbell's sunshiney outlook - which came just days after another analyst expressed a similar sentiment about the sector - meant the sector led the FTSE 100's risers by the middle of the morning, with Persimmon and Barratt both rising two per cent to 1,919.5p and 520.25p respectively, while Berkeley Group rose 1.2 per cent to 2,925p, and Taylor Wimpey rose 1.2 per cent to 179p.