What will be the major product on chlorination of m-nitrophenol?

I came across a question asking for the major product on chlorination of m-nitrophenol. In my opinion the deactivating nature of nitro group should control the regioselectivity, but I found out the answer to be 4-chloro-3-nitrophenol. But why is the activating nature of the hydroxyl group dominating over the deactivating nature of the nitro group? 





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> But why is the activating nature of hydroxyl group dominating over the deactivating nature of Nitro group? 
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This is the precise reason why [Picric acid](http://en.m.wikipedia.org/wiki/Picric_acid) is formed. ( [Check here](http://www.chemguide.co.uk/organicprops/phenol/ring.html) )  

The activating nature of the $\ce{-OH}$ group is strong enough to counter the deactivating nature of the nitro groups.  

Look at Ron's comment on the question over [here](https://chemistry.stackexchange.com/questions/25131/how-do-we-know-whether-we-will-get-a-mono-substituted-or-tri-substituted-product).  

Even methyl group sustains deactivating nature of nitro group in the formation of [TNT](http://en.m.wikipedia.org/wiki/Trinitrotoluene). So no wonder phenolic group, a better activator, dominates. 


The phenolic group increases electron density on ortho para (making it o-p director) while nitro groups decrease e-density on the o-p positions (making it a meta director). When both these effects act simultaneously, the question is who wins and is the density on o-p carbons less than corresponding meta ones? (as that would decide where the electrophile will attack) 


Resonace structures of the groups gives the solution.  

In nitro group: 


![enter image description here](https://i.stack.imgur.com/cky3T.png) 


There are three charged atoms bonded together in the $\ce{-NO\_2}$ molecule. This is less table than the positive charge bearing oxygen atom in phenolic group's resonance structure: 


![enter image description here](https://i.stack.imgur.com/0sJ97.png) 


Hence phenolic group wins!! 


Coming back to the given starting reactant: 


![enter image description here](https://i.stack.imgur.com/rqLbL.png) 


So now we consider the dominating ortho-para effect of phenolic group over the meta-directing effect of nitro groups to get 4-chloro-3-nitrophenol: 


![enter image description here](https://i.stack.imgur.com/GuStv.png)


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