Were more mines closed under labour than under Thatcher?

Straight answer 160 mines were closed under Thatcher’s time in office (1979–1990) Approx 11 years

290 were closed under Harold Wilson’s premierships alone (1965–1969 1974–1975) Approx 10 years

The more important detail is the number of deep pits closed, disregarding small mines, sometimes privately owned

Labour in total closed 371 deep pits.

Clement Atlee closed 101 in the early days after nationalisation

Harold Wilson closed 235 between 1964 and 1970 and 18 in the years after the miners strike during Heath’s term in office

James Callaghan continued the policy of supporting the NUM by closing just 4 mines in 1977- 1979

Blair closed 10 in 10 years and Brown 1.

Thatcher closed 115 deep pits.

MacMillan closed the most: 246 during the times that “we never had it so good” 1957- 1963 Previously Churchill had closed 78 and Eden 35. There was little protest at mine closures during this time or throughout Wilson’s time in office.

Heath closed 24 pits but disputes over pay and 2 miner’s strikes resulted in him losing power when he called a general election hoping to gain popular support in refusing to agree to the miner’s claims. This gave the NUM the impression that they held a great deal of political influence.

Although the number on mines closed by Thatcher was just marginally more than Atlee it was a much greater percentage of mines remaining. Cheap imports oil and nuclear power had made British coal less profitable and the militant miner’s union had put politics before production. The decline continued under Major with 55 pits closed and the last deep pit in Britain shut down in December 2015 due to lack of orders. By 2025 it is planned there will be no coal fired power stations left in the UK.

The official figures indicate that of the 3,000 mines closed in the last century, and 1.1 million workers made redundant, 169 pits (5.6%), and 0.1 million miners (9%) were scrapped under her 11 year premiership (11%), so relatively kind to the industry, and well below 700+ Closed by Labour ministers for Coal:

Year  Tonnes Miners  Total Opencast
         (M)    (K)  Mines    Mines
1913     292  1,107  3,024
1920     233  1,191  2,571 
1938     231    776  1,860
1947     200    707  1,667     125 (Attlee            1945-51 - ~230 mines)
1952     238    712  1,426      92 
1964     198    502    989      46 (Wilson            1964-70 - ~500 mines)
1974     110    253    308      58 (Wilson / Callahan 1974-79 - ~ 30 mines)  
1979     122    242    277      58 (Thatcher          1979-90 -  169 mines)
1991      94     38    108      58 (Major             1990-97 -   28 mines)  
1997      48     14     80      58 (Blair / Brown     1997-10 -   42 mines)
2010      18      6     38      28 (Cameron / Clegg   2010-15 -   42 mines)
2015       9      2     22      17 (Cameron           2015-17 -   16 mines)
2017       3      1     20      17 (May               2016-19 -    2 mines)

From: Historical coal data: coal production, availability and consumption

You have bee given many answers by others but I suspect that there are a couple of issues that lie behind the question. To start with Mrs Thatcher was unlikely to have closed more that Labour simply because over the years most of the mines had already been closed when she came to power. Mrs Thatcher is criticised at very opportunity just because she was PM of a Conservative government. I don't intend to discus the political problems caused by Mr Scargill and the misuse of power by the trade unions here but stick to some of the reasons regarding the demise of the coal industry and why. For me 3 stand out which have nothing to do with Mrs Thatcher or the Conservatives but which are ignored by her critics. 1) The discovery of oil and its development at the turn of the 20th century and the subsequent decision to use oil in the British Fleet meant that the biggest user of coal ceased to be a buyer. Oil was more efficient , cleaner and did not spontaneously combust causing many ships to blow up with the deaths of thousands of sailors and merchantmen. 2) After the terrible smog of the 1940s/1950s which killed many thousands, it was decided to introduce the Clean Air Act. Overnight households could no longer buy coal. Again oil was cleaner and more efficient. During the 50s and 60s cheap coal became available from elsewhere in Europe. The combination of all these factors plus other not mentioned here were the cause of the demise of the British coal industry.
As stated earlier I have deliberately kept away from the politics that have concerned many on the left. Bit if people would study the facts they could not be so critical of Mrs Thatcher. The dye was cast long before she became PM.