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| Do you agree with the Czech Republic becoming a member state of the European Union in accordance with the Treaty on the Accession of the Czech Republic to the European Union? | ||||||||||||||||||||||
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 A referendum on joining the European Union was held in the Czech Republic on 13 and 14 June 2003. The proposal was supported by 77% of voters, with a turnout of 55%. The Czech Republic joined the EU on 1 May 2004.
As of 2025, this was the most recent and only national referendum in the Czech Republic.
The table lists the political parties which were represented in the parliament at the time of the referendum.
Opinion polls in the run-up to the referendum showed support for joining from 63% to over 70%, with the highest support among younger, wealthier and better educated people. [1]
| Date | Agency | Yes | No | Undecided | 
|---|---|---|---|---|
| 19–26 May 2003 | CVVM [2] | 63% | 22% | 15% | 
| 7–14 April 2003 | CVVM [3] | 58% | 24% | 18% | 
| March 2003 | STEM [4] | 51% | 16% | 33% | 
| 3–10 March 2003 | CVVM [5] | 59% | 22% | 19% | 
| February 2003 | STEM [6] | 50% | 32% | 18% | 
| 3–10 February 2003 | CVVM [7] | 59% | 23% | 18% | 
| 28 January 2003 | STEM [8] | 47% | 19% | 34% | 
| December 2002 | STEM [8] | 48% | 21% | 31% | 
| November 2002 | STEM [8] | 48% | 19% | 33% | 
| 17–24 October 2002 | CVVM [9] | 47% | 18% | 23% | 
| September 2002 | STEM [10] | 43% | 20% | 37% | 
| 5–12 June 2002 | CVVM [11] | 42% | 17% | 41% | 
| 22–29 April 2002 | CVVM [12] | 40% | 19% | 41% | 
| March 2002 | STEM [13] | 46% | 19% | 35% | 
| November 2001 | STEM [6] | 47% | 19% | 34% | 
| 2–9 May 2001 | STEM [14] | 40% | 22% | 38% | 
| 5–12 March 2001 | STEM [15] | 45% | 18% | 37% | 
| October 2000 | STEM [16] | 48% | 15% | 37% | 
| May 2000 | STEM [16] | 42% | 16% | 42% | 
| September 1999 | STEM [16] | 44% | 19% | 39% | 
| April 1999 | STEM [16] | 46% | 14% | 40% | 
| April 1997 | STEM [16] | 50% | 16% | 34% | 
| August 1996 | STEM [16] | 46% | 13% | 41% | 
 
 | Choice | Votes | % | |
|---|---|---|---|
| For | 3,446,758 | 77.33 | |
| Against | 1,010,448 | 22.67 | |
| Total | 4,457,206 | 100.00 | |
| Valid votes | 4,457,206 | 97.79 | |
| Invalid/blank votes | 100,754 | 2.21 | |
| Total votes | 4,557,960 | 100.00 | |
| Registered voters/turnout | 8,259,525 | 55.18 | |
| Source: Direct Democracy | |||